Status 27.01.2022
Out of curiosity I checked my survey answers and found out that a big amount of answers were just blank. I found out that the answers take very long to load / to send - if you close the survey before the answers are sent, it will send a blank form. I am quite dissapointed in that, because I think I have lost some great answers to that error.
Today or tomorrow, I'll send out the survey again with a disclaimer about that error and will hope for the best.
Update 28.01: The problem was fixed.