[SOLVED] ZFS Pool creates error while resilvering

It's clearly not a Proxmox issue but a drive problem. Start a long self-test (smartctl -t long /dev/sdb, like I wrote before) and wait for several hours to determine if the drive itself detects any problems. That's usually enough for a RMA.
Code:
    ~  sudo smartctl -a /dev/sda                                                                                                                                                                           ✔
smartctl 7.4 2023-08-01 r5530 [x86_64-linux-6.1.106-1-MANJARO] (local build)
Copyright (C) 2002-23, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF INFORMATION SECTION ===
Model Family:     Western Digital Red
Device Model:     WDC WD20EFZX-68AWUN0
Serial Number:    WD-WX92DA0LJJVZ
LU WWN Device Id: 5 0014ee 2be67ae24
Firmware Version: 81.00A81
User Capacity:    2.000.398.934.016 bytes [2,00 TB]
Sector Sizes:     512 bytes logical, 4096 bytes physical
Rotation Rate:    5400 rpm
Form Factor:      3.5 inches
Device is:        In smartctl database 7.3/5528
ATA Version is:   ACS-3 T13/2161-D revision 5
SATA Version is:  SATA 3.1, 6.0 Gb/s (current: 6.0 Gb/s)
Local Time is:    Tue Sep 24 10:54:16 2024 CEST
SMART support is: Available - device has SMART capability.
SMART support is: Enabled

=== START OF READ SMART DATA SECTION ===
SMART overall-health self-assessment test result: PASSED

General SMART Values:
Offline data collection status:  (0x00)    Offline data collection activity
                    was never started.
                    Auto Offline Data Collection: Disabled.
Self-test execution status:      (  25)    The self-test routine was aborted by
                    the host.
Total time to complete Offline
data collection:         (22260) seconds.
Offline data collection
capabilities:              (0x11) SMART execute Offline immediate.
                    No Auto Offline data collection support.
                    Suspend Offline collection upon new
                    command.
                    No Offline surface scan supported.
                    Self-test supported.
                    No Conveyance Self-test supported.
                    No Selective Self-test supported.
SMART capabilities:            (0x0003)    Saves SMART data before entering
                    power-saving mode.
                    Supports SMART auto save timer.
Error logging capability:        (0x01)    Error logging supported.
                    General Purpose Logging supported.
Short self-test routine
recommended polling time:      (   2) minutes.
Extended self-test routine
recommended polling time:      ( 239) minutes.
SCT capabilities:            (0x303d)    SCT Status supported.
                    SCT Error Recovery Control supported.
                    SCT Feature Control supported.
                    SCT Data Table supported.

SMART Attributes Data Structure revision number: 16
Vendor Specific SMART Attributes with Thresholds:
ID# ATTRIBUTE_NAME          FLAG     VALUE WORST THRESH TYPE      UPDATED  WHEN_FAILED RAW_VALUE
  1 Raw_Read_Error_Rate     0x002f   200   200   051    Pre-fail  Always       -       0
  3 Spin_Up_Time            0x0027   196   196   021    Pre-fail  Always       -       3158
  4 Start_Stop_Count        0x0032   100   100   000    Old_age   Always       -       15
  5 Reallocated_Sector_Ct   0x0033   200   200   140    Pre-fail  Always       -       0
  7 Seek_Error_Rate         0x002e   200   200   000    Old_age   Always       -       0
  9 Power_On_Hours          0x0032   100   100   000    Old_age   Always       -       10
 10 Spin_Retry_Count        0x0032   100   253   000    Old_age   Always       -       0
 11 Calibration_Retry_Count 0x0032   100   253   000    Old_age   Always       -       0
 12 Power_Cycle_Count       0x0032   100   100   000    Old_age   Always       -       11
192 Power-Off_Retract_Count 0x0032   200   200   000    Old_age   Always       -       9
193 Load_Cycle_Count        0x0032   200   200   000    Old_age   Always       -       6
194 Temperature_Celsius     0x0022   126   108   000    Old_age   Always       -       21
196 Reallocated_Event_Count 0x0032   200   200   000    Old_age   Always       -       0
197 Current_Pending_Sector  0x0032   200   200   000    Old_age   Always       -       0
198 Offline_Uncorrectable   0x0030   100   253   000    Old_age   Offline      -       0
199 UDMA_CRC_Error_Count    0x0032   200   200   000    Old_age   Always       -       0
200 Multi_Zone_Error_Rate   0x0008   200   200   000    Old_age   Offline      -       0

SMART Error Log Version: 1
ATA Error Count: 529 (device log contains only the most recent five errors)
    CR = Command Register [HEX]
    FR = Features Register [HEX]
    SC = Sector Count Register [HEX]
    SN = Sector Number Register [HEX]
    CL = Cylinder Low Register [HEX]
    CH = Cylinder High Register [HEX]
    DH = Device/Head Register [HEX]
    DC = Device Command Register [HEX]
    ER = Error register [HEX]
    ST = Status register [HEX]
Powered_Up_Time is measured from power on, and printed as
DDd+hh:mm:SS.sss where DD=days, hh=hours, mm=minutes,
SS=sec, and sss=millisec. It "wraps" after 49.710 days.

Error 529 occurred at disk power-on lifetime: 4 hours (0 days + 4 hours)
  When the command that caused the error occurred, the device was active or idle.

  After command completion occurred, registers were:
  ER ST SC SN CL CH DH
  -- -- -- -- -- -- --
  04 61 46 00 00 00 a0  Device Fault; Error: ABRT

  Commands leading to the command that caused the error were:
  CR FR SC SN CL CH DH DC   Powered_Up_Time  Command/Feature_Name
  -- -- -- -- -- -- -- --  ----------------  --------------------
  ef 03 46 00 00 00 a0 08      00:09:11.378  SET FEATURES [Set transfer mode]
  ec 00 00 00 00 00 a0 08      00:09:11.360  IDENTIFY DEVICE
  ec 00 00 00 00 00 a0 08      00:09:11.345  IDENTIFY DEVICE
  ef 03 46 00 00 00 a0 08      00:09:11.345  SET FEATURES [Set transfer mode]

Error 528 occurred at disk power-on lifetime: 4 hours (0 days + 4 hours)
  When the command that caused the error occurred, the device was active or idle.

  After command completion occurred, registers were:
  ER ST SC SN CL CH DH
  -- -- -- -- -- -- --
  04 61 46 00 00 00 a0  Device Fault; Error: ABRT

  Commands leading to the command that caused the error were:
  CR FR SC SN CL CH DH DC   Powered_Up_Time  Command/Feature_Name
  -- -- -- -- -- -- -- --  ----------------  --------------------
  ef 03 46 00 00 00 a0 08      00:09:11.345  SET FEATURES [Set transfer mode]
  ec 00 00 00 00 00 a0 08      00:09:11.326  IDENTIFY DEVICE
  ec 00 00 00 00 00 a0 08      00:09:11.312  IDENTIFY DEVICE
  ef 03 46 00 00 00 a0 08      00:09:11.312  SET FEATURES [Set transfer mode]

Error 527 occurred at disk power-on lifetime: 4 hours (0 days + 4 hours)
  When the command that caused the error occurred, the device was active or idle.

  After command completion occurred, registers were:
  ER ST SC SN CL CH DH
  -- -- -- -- -- -- --
  04 61 46 00 00 00 a0  Device Fault; Error: ABRT

  Commands leading to the command that caused the error were:
  CR FR SC SN CL CH DH DC   Powered_Up_Time  Command/Feature_Name
  -- -- -- -- -- -- -- --  ----------------  --------------------
  ef 03 46 00 00 00 a0 08      00:09:11.312  SET FEATURES [Set transfer mode]
  ec 00 00 00 00 00 a0 08      00:09:11.294  IDENTIFY DEVICE
  ec 00 00 00 00 00 a0 08      00:09:11.279  IDENTIFY DEVICE
  ef 03 46 00 00 00 a0 08      00:09:11.279  SET FEATURES [Set transfer mode]

Error 526 occurred at disk power-on lifetime: 4 hours (0 days + 4 hours)
  When the command that caused the error occurred, the device was active or idle.

  After command completion occurred, registers were:
  ER ST SC SN CL CH DH
  -- -- -- -- -- -- --
  04 61 46 00 00 00 a0  Device Fault; Error: ABRT

  Commands leading to the command that caused the error were:
  CR FR SC SN CL CH DH DC   Powered_Up_Time  Command/Feature_Name
  -- -- -- -- -- -- -- --  ----------------  --------------------
  ef 03 46 00 00 00 a0 08      00:09:11.279  SET FEATURES [Set transfer mode]
  ec 00 00 00 00 00 a0 08      00:09:11.261  IDENTIFY DEVICE
  ec 00 00 00 00 00 a0 08      00:09:11.245  IDENTIFY DEVICE
  ef 03 46 00 00 00 a0 08      00:09:11.245  SET FEATURES [Set transfer mode]

Error 525 occurred at disk power-on lifetime: 4 hours (0 days + 4 hours)
  When the command that caused the error occurred, the device was active or idle.

  After command completion occurred, registers were:
  ER ST SC SN CL CH DH
  -- -- -- -- -- -- --
  04 61 46 00 00 00 a0  Device Fault; Error: ABRT

  Commands leading to the command that caused the error were:
  CR FR SC SN CL CH DH DC   Powered_Up_Time  Command/Feature_Name
  -- -- -- -- -- -- -- --  ----------------  --------------------
  ef 03 46 00 00 00 a0 08      00:09:11.245  SET FEATURES [Set transfer mode]
  ec 00 00 00 00 00 a0 08      00:09:11.227  IDENTIFY DEVICE
  ec 00 00 00 00 00 a0 08      00:09:11.212  IDENTIFY DEVICE
  ef 03 46 00 00 00 a0 08      00:09:11.212  SET FEATURES [Set transfer mode]

SMART Self-test log structure revision number 1
Num  Test_Description    Status                  Remaining  LifeTime(hours)  LBA_of_first_error
# 1  Extended offline    Aborted by host               90%        10         -
# 2  Extended offline    Completed without error       00%        10         -

Selective Self-tests/Logging not supported

The above only provides legacy SMART information - try 'smartctl -x' for more