[cobramite]

My M50i did this 4 or 5 times while I owned it. Always came back to normal when I started it the next day.

[BRB-Prsch928S]

My 2021 40i did this as well. It would only drop the bass every few months and would only come back after the car went totally asleep (like overnight). Dealer tried software update, issue returned, and they then replaced the amp under warranty a few months ago. So far, so good.

[R3v1v3]

A software update was also done in mine but didn’t help. From my knowledge, amp replacement is the only way to resolve this issue. I never bothered getting it done as my lease is done and I’ve got another one on the way.

[dragos.pope]

The same thing happened to me on a 2021 G05. I went to the BMW dealership and after they updated the car's software, the diagnosis was: the amplifier is burnt. They replaced it under warranty