Unable to add working routines to existing experiment

I hope I can still run it online.

Unfortunately, I cannot run my experiment online. I get an Unspecified Javascript Error, exactly the same as I described in the first part of this post. It has to do with the function requestAnimationFrame. Removing requests for frame rate results in the same errors as reported in the added section of that post.
Going back to 2020.1.3 is now no longer an option either.