Adobe Acrobat Pro - fill and sign doesn't work - please help!

Hello everyone,

I was in contact with Adobe customer service all afternoon yesterday, but they didn't know what was going on either, hopefully you can help:

We have forms with fillable fields and signature fields and we sometimes partially fill these in in advance and then we send it to the recipient and they fill or change the indicated fields. But now suddenly, while nothing has changed and we have done the previous method this way hundreds of times in recent months, it no longer works. The recipient does not see the fillable fields and the signature fields. A signature field is added on the last page that I didn't indicate. I also tried with the classic version, reinstalled Adobe, etc. but nothing changes. Does anyone know what's going on? I recorded my screen to show what happens at the sender and receiver. See attachment It also seems like sometimes a different version is used by Adobe than other times. Sometimes I only have to enter the recipient's email address and other times I have to enter the email address and name. Thank you very much in advance!