Copy and Cut sometimes don't work
Based on this post, the following worked for me.

Check if the pboard daemon is running:

launchctl list | grep com.apple.pboard


If the pboard daemon is running, then stop and start it.  If it's not running, start it:

launchctl stop com.apple.pboard
launchctl start com.apple.pboard


Then, you may need to restart the application(s) where cut-and-paste is not working.