I have Windows 10, 22H2 and my NIK filters still work. I don't have DXO. You might wish to check if Microsoft is still supporting Windows 21h2. I could be wrong, but that might be what's affecting your NIK filters. Or perhaps you should re-install the NIK filters again.
Thanks for your help. I did not install them. I copied the directory from an older PS version and they worked. Perhaps I should install them... if I can find the old files. The PS versions were recently updated: 24.5 regular and 24.6 beta.