Gimp 2.10 crashing every time I try to cut or copy

[thesun]

I hope someone here will help with a problem that repeatedly happens and basically (overnight, it seems!) has made GIMP unusable:

I open a photo.  Highlight some area.  Hit either Edit > Cut, Edit > Copy, or Cntl-x or Cntl-c, and poof, GIMP crashes.  Every time.

It doesn't seem to matter the size of the document or area I'm trying to copy.

I saw some thread on another forum saying if on has CopyQ installed that may cause issues, but I don't believe I do.  (I'm running Lubuntu 20.04LTS, a vanilla install, nothing modified.  It's LXQt, if that matters.  And my system is a newish Dell with 40GB of RAM, so I doubt it's a memory problem.)

I desperately need to fix this or find a work around.  Here's the output when I run GIMP from the command line:

me@home:~$ gimp
using gegl copy

(gimp:248888): Gdk-CRITICAL **: 22:06:25.414: IA__gdk_window_get_events: assertion 'GDK_IS_WINDOW (window)' failed

(gimp:248888): Gdk-CRITICAL **: 22:06:25.414: IA__gdk_window_set_events: assertion 'GDK_IS_WINDOW (window)' failed
The program 'gimp' received an X Window System error.
This probably reflects a bug in the program.
The error was 'BadWindow (invalid Window parameter)'.
(Details: serial 95997 error_code 3 request_code 18 minor_code 0)
(Note to programmers: normally, X errors are reported asynchronously;
that is, you will receive the error a while after causing it.
To debug your program, run it with the --sync command line
option to change this behavior. You can then get a meaningful
backtrace from your debugger if you break on the gdk_x_error() function.)

(script-fu:248910): LibGimpBase-WARNING **: 22:06:25.457: script-fu: gimp_wire_read(): error

Thank you in advance for any help.