64 questions are beyond the ability of formranger.
I shared a link with you.to build your own script.
You could also change your design. A form for each school would lower the number of classes and formranger would likely work.
You can create a document with links to each form. One link would take them to the document where they click on the correct form.
If you have nothing better to do, keep trying to get formranger to work with 64 dropdown questions. A better use of your time would be to change your design to what you know works.
You can create your own script.
Joe Schmidt