First time post as I only recently decided to try Qubes and have installed 4.0.3 on my dual Xeon E5465 server which has 24Gb RAM and two 160Gb HDD (one is used for Qubes and one for Backups).
I have most things working and have installed Fedora-32 template. Set this as default template for all Fedora AppVMs. I got audio working in my Debian-10 AppVM. I have now created two HVM - Linux Mint 20.1 and Windows 10. These all work fine. During install I decided to use Sys-Net for network and USB, although I only have PS/2 keyboard and mouse on this machine. USB does work fine in AppVM.
I am now getting random freeze of all keyboard and mouse and after waiting several hours (until no HDD activity), all I can do is total power off. On restart all seems to be fine. What can I do to troubleshoot this?