I am having a few issues, I keep trying to edit this set of photos and every now and then they will freeze up and come back with this (often after using Nik Collection), and all of the different photos will be like this even though I have only. started on one.
If I export as JPG then the file is fine, however if I save as a PSD and reopen I need to quit and restart the computer to be able to get the file back to normal?
You could try ...
(1) ... to disable the use of GPU in Edit > Preferences > Performance
(2) ... and look for help in many posts and articles concerning the NIK collection, matching your system.