If you create even a trivial single actor project with minimal code e.g.:
https://www.greenfoot.org/scenarios/35367
The site cannot execute it and there are no diagnostic messages from TeaVM:
INFO: Running TeaVM
Sorry for the delay in addressing this - due to travel and annual leave over the summer. I believe this is now fixed and all the scenarios which can be fixed are currently being processed to work again. (Your linked scenario has been done just as I write this.) Let us know if you spot any other problems.