Make sure you aren't launching any of the processes elevated. That's the only thing I can think of that might cause issues.
No, I'm not launching the processes elevated, so all clear there.
However, I discovered something very interesting and I now believe that the command line to disable/enable the double-clicking does not work. That is, if I launch DOpus and go into Preferences to disable and re-enable the double-clicking, that works!
I'm happy with this as the solution because it sure beats rebooting but it would be nice to have the dopusrt.exe command line working, so that I can incorporate it into my explorer.exe restart script.
I found something else that's interesting...
If I run the command to disable the double-clicking, when I go into Preferences, although it still shows it as enabled, it has, however, been successfully disabled. Thus, this command line definitely works.
But when I run the command to enable the double-clicking, no change whatsoever; thus, this command line seems not to be working.
I tried it earlier and it works OK here.
Hmmm, interesting.
And you're on Windows 11?
Absolutely not. 
(Outside of test/dev VMs.)
lol! 