Thanks for getting back to me. I did try all the suggestions but it's still more or less unusable as it crashes randomly. Having had a very stable application before Windows 11 I don't understand why suddenly any of these things would become problematic if Affinity is ostensibly stable enough to run on Windows 11. For me the problem evidently lies with Affinity. I'm running the following:-
Device name DESKTOP-IMQJ0D9
Processor Intel(R) Core(TM) i9-7960X CPU @ 2.80GHz 2.81 GHz
Installed RAM 64.0 GB (63.7 GB usable)
Device ID EF7E1E4A-A5A8-407C-A562-BAC561EC2524
Product ID 00326-10000-00000-AA529
System type 64-bit operating system, x64-based processor
Pen and touch Pen support
Edition Windows 11 Home
Version 21H2
Installed on 27/05/2022
OS build 22000.832
Experience Windows Feature Experience Pack 1000.22000.832.0