Vega passhthrough hardlocks kernel 5.4.0

Had a previously working GPU passhthrough setup.
With the bus reset disable patch applied, can shutdown and reboot the VM without any issue.

AMD Ryzen 3600x, MSI MEG x570 Unify
Host: Red Devil Vega64
Host OS: Ubuntu 19.10, linux_5.3.0-29
Guest: Red Devil Vega56
Guest OS: Windows 10

After the recent update to 20.04 (linux_5.4.0-34 with the same bus reset disable changes), shutting down the VM will result in a lock where the system doesn’t respond. Magic SYSREQ still works though. Everything still works if booted with the 5.3.0-29 kernel.

Anyone having a similar issue?