Hi,
please share the configurations of some affected VMs, qm config ID replacing ID with the actual numerical ID and the output of pveversion -v. What kind of guest OS and kernel is running inside the VM?
qm config 100
bios: ovmf
boot: order=scsi0;ide2;net0
cores: 1
cpu: x86-64-v2-AES
efidisk0: local:100/vm-100-disk-0.qcow2,efitype=4m,pre-enrolled-keys=1,size=528K
ide2: local:iso/debian-13.0.0-amd64-DVD-1.iso,media=cdrom,size=3900480K
memory: 1024
meta: creation-qemu=9.2.0,ctime=1764965128
name: trixie0
net0: virtio=02:00:00:61:76:59,bridge=vmbr0,firewall=1
numa: 0
ostype: l26
scsi0: local:100/vm-100-disk-1.qcow2,iothread=1,size=10G
scsihw: virtio-scsi-single
smbios1: uuid=d424b9b6-95eb-40f4-a120-c391b852a973
sockets: 1
vmgenid: f4d6c179-1994-48b9-99c1-16c4ad5626d5
_______
qm config 101
bios: ovmf
boot: order=scsi0;ide2;net0
cores: 1
cpu: x86-64-v2-AES
efidisk0: local:101/vm-101-disk-0.qcow2,efitype=4m,pre-enrolled-keys=1,size=528K
ide2: local:iso/debian-13.0.0-amd64-DVD-1.iso,media=cdrom,size=3900480K
memory: 1024
meta: creation-qemu=9.2.0,ctime=1764965128
name: moodle
net0: virtio=02:00:00:61:76:59,bridge=vmbr0,firewall=1
numa: 0
ostype: l26
scsi0: local:101/vm-101-disk-1.qcow2,iothread=1,size=10G
scsihw: virtio-scsi-single
smbios1: uuid=d424b9b6-95eb-40f4-a120-c391b852a973
sockets: 1
vmgenid: d6c87fef-e8b6-46aa-a0b8-e8c96aee4b4c
_____
qm config 500
bios: ovmf
boot: order=scsi0;ide2;net0
cores: 4
cpu: x86-64-v2-AES
efidisk0: local:500/vm-500-disk-0.qcow2,efitype=4m,pre-enrolled-keys=1,size=528K
ide2: local:iso/debian-13.0.0-amd64-DVD-1.iso,media=cdrom,size=3900480K
memory: 8192
meta: creation-qemu=9.2.0,ctime=1764965128
name: mcvFR
net0: virtio=02:00:00:61:76:59,bridge=vmbr0,firewall=1
numa: 0
ostype: l26
scsi0: local:500/vm-500-disk-1.qcow2,iothread=1,size=128G
scsihw: virtio-scsi-single
smbios1: uuid=d424b9b6-95eb-40f4-a120-c391b852a973
sockets: 1
vmgenid: abfe5f40-3d64-4002-aa10-11faf3650f72
_____
pveversion -v
proxmox-ve: 9.1.0 (running kernel: 6.17.2-2-pve)
pve-manager: 9.1.2 (running version: 9.1.2/9d436f37a0ac4172)
proxmox-kernel-helper: 9.0.4
proxmox-kernel-6.17.2-2-pve-signed: 6.17.2-2
proxmox-kernel-6.17: 6.17.2-2
amd64-microcode: 3.20250311.1
ceph-fuse: 19.2.3-pve1
corosync: 3.1.9-pve2
criu: 4.1.1-1
frr-pythontools: 10.4.1-1+pve1
ifupdown2: 3.3.0-1+pmx11
intel-microcode: 3.20250812.1~deb13u1
libjs-extjs: 7.0.0-5
libproxmox-acme-perl: 1.7.0
libproxmox-backup-qemu0: 2.0.1
libproxmox-rs-perl: 0.4.1
libpve-access-control: 9.0.4
libpve-apiclient-perl: 3.4.2
libpve-cluster-api-perl: 9.0.7
libpve-cluster-perl: 9.0.7
libpve-common-perl: 9.1.0
libpve-guest-common-perl: 6.0.2
libpve-http-server-perl: 6.0.5
libpve-network-perl: 1.2.3
libpve-rs-perl: 0.11.3
libpve-storage-perl: 9.1.0
libspice-server1: 0.15.2-1+b1
lvm2: 2.03.31-2+pmx1
lxc-pve: 6.0.5-3
lxcfs: 6.0.4-pve1
novnc-pve: 1.6.0-3
proxmox-backup-client: 4.1.0-1
proxmox-backup-file-restore: 4.1.0-1
proxmox-backup-restore-image: 1.0.0
proxmox-firewall: 1.2.1
proxmox-kernel-helper: 9.0.4
proxmox-mail-forward: 1.0.2
proxmox-mini-journalreader: 1.6
proxmox-offline-mirror-helper: 0.7.3
proxmox-widget-toolkit: 5.1.2
pve-cluster: 9.0.7
pve-container: 6.0.18
pve-docs: 9.1.1
pve-edk2-firmware: not correctly installed
pve-esxi-import-tools: 1.0.1
pve-firewall: 6.0.4
pve-firmware: 3.17-2
pve-ha-manager: 5.0.8
pve-i18n: 3.6.5
pve-qemu-kvm: 10.1.2-4
pve-xtermjs: 5.5.0-3
qemu-server: 9.1.1
smartmontools: 7.4-pve1
spiceterm: 3.4.1
swtpm: 0.8.0+pve3
vncterm: 1.9.1
zfsutils-linux: 2.3.4-pve1
___
All use 6.12.57+deb13-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.12.57-1 (2025-11-05) x86_64