desktop 16.5.1 2 vms. update to BigSur 11.6 now I can not run two VMs at the same time. Solved?

Hi,

After updating to BigSur I can no longer run two vms at the same time. It worked fine before the OS update.

MBP 16" 2019 16gb AMD Radeon Pro 5500 4G (2 external displays, laptop closed)

steps
Start Vm win 8.1
start Vm win 10

After 30 seconds to 5 minutes, 8.1 screen goes black.

stop win 10
8.1 starts working.


vms have a resource conflict?

Just checked RAM on vms
win 10 4gb ram
win 8.1 8gb ram

Dropped the 8.1 vm to 4GB and re-started 8.1 and win 10.

It works now (10+ minutes so far.) I posted this in case it helps someone else.