args: -cpu host,-hypervisor prevents Windows boot since WU 2026-01 ( only AMD ? )

[_gabriel]

Seems I'm encountering a bug.
Host CPU is AMD 7302P
( EPYC Zen2 "Rome" ) on HPE DL325 G10.
PVE 8.4 ( Enterprise version 8.4.16 )
proxmox-ve: 8.4.0
running kernel: 6.8.12-18-pve
pve-manager: 8.4.16
pve-qemu-kvm: 9.2.0-7
qemu-server: 8.4.5

VM guest : Windows 10 ESU, 2019 , 2022 , 2025 , UEFI (No Secure boot ), SeaBIOS
works fine with args: -cpu host,-hypervisor
Once January 2026 Windows Update,
Windows no longer boots,
VM hangs before the spinning circle.
I haven't another AMD EPYC at the hand
and not reproducible with a Intel E-2346 on PVE 8.4

Anyone can test ?