Bluetooth chip

I use hearing aids which I connect to my iPhone 12 mini for phone calls. After a few weeks of getting the phone, it started crackling (static) during phone call and the crackling got worse with each phone call. After researching the issue online, I found out that’s it’s a widespread problem for all hearing aid users who have any of the iPhone 12 models. Apple was meant to have fixed up the bug with a new update in Dec 2020, but the fix is only short term. Every time I reset all settings on my phone the crackling stops but after the 3rd-4th phone call it starts up again and I have to reset the phone. It’s becoming really inconvenient. Does anyone know if Apple is going to try fix the issue permanently? Any advice would be HUGELY appreciated please!