Auto-size font in form field has mysteriously stopped working

We have a client intake fillable form that I designed and have been using for years, and somehow, a new client has sent the form back to us and most - but not all - of the form fields have mysteriously stopped auto-sizing the font so now the data is cut off.

Every field still has the same settings as before.  In fact, if I add garbage data of my own to existing blank form fields it properly scales the font.  Attempting to edit fields with this error shows the font properly scale while I am editing the text, but it immediately snaps back to full size once I leave that field.

Due to client confidentiality I cannot provide the document for review, but nothing is making sense and I don't have a clue how this could have even happened in the first place.  Can anyone provide some assistance?  I can't find anything else in the discussions that has helped.