This bug is finally solved. I first tried comparing the records for athletifiselect.com (which still worked fine) to athleti.fi, and then recreating the missing domain records manually, but that just introduced a whole bunch of other weird SSL errors I've never experienced before. So I just deleted the domain connection again off Amplify, disconnected the prod branch, let it wait for 6 hours and then recreated it, and then it magically worked 🤷♂️
This bug is finally solved. I first tried comparing the records for athletifiselect.com (which still worked fine) to athleti.fi, and then recreating the missing domain records manually, but that just introduced a whole bunch of other weird SSL errors I've never experienced before. So I just deleted the domain connection again off Amplify, disconnected the prod branch, let it wait for 6 hours and then recreated it, and then it magically worked 🤷♂️