q35 Clear Linux - freezes with scp

[apwiggins]

For several months, I've been running Clear Linux q35-based VMs using this method. https://docs.01.org/clearlinux/latest/get-started/virtual-machine-install/proxmox.html
After a recent Proxmox VE update, these q35-based VMs will 'freeze'.

Steps to reproduce:
To create the condition, boot the VM.
Console is available via Proxmox WebUI. Can also remotely ssh to the VM.
Using a remote workstation, use scp to copy a large file to the q35-based Clear Linux VM.
scp connects but cannot instantiate the transfer.
Proxmox WebUI shows a disconnect in logs (below). Proxmox WebUI console is no longer available (frozen state).

Relevant logs:

Mar 21 07:42:06 pve2 pvedaemon[769130]: start VM 112: UPID:pve2:000BBC6A:005A1CE4:6238567E:qmstart:112:root@pam:
Mar 21 07:42:06 pve2 systemd[1]: Started 112.scope.
Mar 21 07:42:06 pve2 systemd-udevd[769149]: Using default interface naming scheme 'v247'
Mar 21 07:42:06 pve2 systemd-udevd[769149]: ethtool: autonegotiation is unset or enabled, the speed and duplex are not writable.
Mar 21 07:42:07 pve2 kernel: device tap112i0 entered promiscuous mode
Mar 21 07:42:07 pve2 systemd-udevd[769149]: ethtool: autonegotiation is unset or enabled, the speed and duplex are not writable.
Mar 21 07:42:07 pve2 systemd-udevd[769149]: ethtool: autonegotiation is unset or enabled, the speed and duplex are not writable.
Mar 21 07:42:07 pve2 systemd-udevd[769152]: ethtool: autonegotiation is unset or enabled, the speed and duplex are not writable.
Mar 21 07:42:07 pve2 systemd-udevd[769152]: Using default interface naming scheme 'v247'.
Mar 21 07:42:07 pve2 kernel: fwbr112i0: port 1(fwln112i0) entered blocking state
Mar 21 07:42:07 pve2 kernel: fwbr112i0: port 1(fwln112i0) entered disabled state
Mar 21 07:42:07 pve2 kernel: device fwln112i0 entered promiscuous mode
Mar 21 07:42:07 pve2 kernel: fwbr112i0: port 1(fwln112i0) entered blocking state
Mar 21 07:42:07 pve2 kernel: fwbr112i0: port 1(fwln112i0) entered forwarding state
Mar 21 07:42:07 pve2 kernel: vmbr0v10: port 2(fwpr112p0) entered blocking state
Mar 21 07:42:07 pve2 kernel: vmbr0v10: port 2(fwpr112p0) entered disabled state
Mar 21 07:42:07 pve2 kernel: device fwpr112p0 entered promiscuous mode
Mar 21 07:42:07 pve2 kernel: vmbr0v10: port 2(fwpr112p0) entered blocking state
Mar 21 07:42:07 pve2 kernel: vmbr0v10: port 2(fwpr112p0) entered forwarding stat
Mar 21 07:42:07 pve2 kernel: fwbr112i0: port 2(tap112i0) entered blocking state
Mar 21 07:42:07 pve2 kernel: fwbr112i0: port 2(tap112i0) entered disabled state
Mar 21 07:42:07 pve2 kernel: fwbr112i0: port 2(tap112i0) entered blocking state
Mar 21 07:42:07 pve2 kernel: fwbr112i0: port 2(tap112i0) entered forwarding state
Mar 21 07:42:07 pve2 pvedaemon[143572]: <root@pam> end task UPID:pve2:000BBC6A:005A1CE4:6238567E:qmstart:112:root@pam: OK
Mar 21 07:43:20 pve2 pmxcfs[1118]: [status] notice: received log
Mar 21 07:43:20 pve2 sshd[770216]: Accepted publickey for root from 192.168.1.199 port 44610 ssh2: RSA SHA256:crJI2Sv1Ere5fWrT+etc
Mar 21 07:43:20 pve2 sshd[770216]: pam_unix(sshd:session): session opened for user root(uid=0) by (uid=0)
Mar 21 07:43:20 pve2 systemd-logind[944]: New session 1097 of user root.
Mar 21 07:43:20 pve2 systemd[1]: Started Session 1097 of user root.
Mar 21 07:43:35 pve2 sshd[770216]: Received disconnect from 192.168.1.199 port 44610:11: disconnected by user  <== point at which event occurs ===
Mar 21 07:43:35 pve2 sshd[770216]: Disconnected from user root 192.168.1.199 port 44610
Mar 21 07:43:35 pve2 sshd[770216]: pam_unix(sshd:session): session closed for user root
Mar 21 07:43:35 pve2 systemd[1]: session-1097.scope: Succeeded.
Mar 21 07:43:35 pve2 systemd-logind[944]: Session 1097 logged out. Waiting for processes to exit.
Mar 21 07:43:35 pve2 systemd-logind[944]: Removed session 1097.

Mar 21 07:43:35 pve2 pmxcfs[1118]: [status] notice: received log

Mar 21 07:46:02 pve2 pmxcfs[1118]: [status] notice: received log