In anticipation of an expert, a few thoughts:
I used to have a similar problem - I couldn't use Gimp and Firefox at the same time (one caused the other to freeze) - but after one update the problem solved itself.
Unfortunately, I don't know which program was the reason: Gimp, Firefox or Windows.
Everything points to Windows and a similar problem (because of gspawn-win32-helper.exe) was reported here:
https://gitlab.gnome.org/GNOME/gimp/issues/4582(pay attention to:
or maybe some non-plug-in files, in any plug-ins folder?)
DIEGO_ARTISTIC_AquarellePlus.py works fine for me for Win10 64bit and Gimp Samj 2.10.14 - 2.10.18.