I've called in help from my GIS co-workers to help problem-solve, but we still get the 500 error.
We've checked publishing permissions, we do not have even 400 questions, checked field types, checked for duplicate naming in the form, deleted anything that made it's way to the portal that might block a 'Publish', updated to the most recent version of Survey123 etc.
Enclosed is the form and a copy of the error msg.
I've private posted with two contributors already but thought that I'd also send one to the group to cover my bases.
Thanks for any help you can extend.