Turtle output window hangs

Help me experts!

I teach AP Comp Sci Principles at a local high school and my students are using repl.it to collaborate on the python turtle projects. But all my students are having the same trouble. They are working in repl.it teams to create python turtle programs. But, after running their programs for awhile, the replit graphics output window hangs. It shows the refreshing spiral for ever and sometimes hangs the ‘stopping’ forever.
At first, closing the output window and reopening it clears the hang, but that stops working.
Running repl.it in a different browser works for a while, but then it stops working.
kill 1 'ing the process from the shell works for awhile, but then it stops working.
Running repl.it from a browser on a different computer works for awhile, but then it stops working.
Deleting the students from their project group and restarting the project group works so far.
Logging out of repl.it and logging back in doesn’t work.
Reloading the browser tab doesn’t work.

Suspicions:
I think there’s a bug in the client side. Maybe when the tab loses focus long enough for the computer to sleep or something like that fails to trigger a refresh graphics panel on gain focus or something. And it’s persistent. Stored locally. Weird.

Has anyone experienced this bug? How do we fix it?

Hi @schickbrian welcome to the community and thank you for your post.

It might be related to a filter on your network. Please see Python Turtle loading issues for more details on this and let me know if the advice helps.