Hello @RyRy1997, the only 3 things I can think of are:- 1. Dust in the microphone port between the 2 buttons 2. Some sort of Water Lock corruption 3. Have you changed the default keyboard and, it's become confused?
You've probably covered 2. and 3. in your actions to date.
Apologies, @RyRy1997, responded too quickly I thought I read somewhere that someone else had issues when moving away from default keyboard, but I can't find it now. Perhaps I dreamt it!