the problem in my eyes is, that there are issues reported for calls since the beginning, however people have many different issues (some on Loudspeaker others on old-school “ear-calls” and others dont have issues at all. That makes it difficult to fix, when its not hardware related. So what does the hardware test say when you test?
As mentioned in the german topic, it was reported by others that had issues, that such things can be caused by taking over system settings from previous phones. So did you ever contact support? Did you try a factory reset to set up from scratch? Yes sure thats annoying as well however for me it would be less annoying then to struggle with this for years.