Headphone channel fades out (strange issue)


I experience a strange headphone issue.

When using my cable headphone with my fp3 (with all updates), after a while - this can be hours oder many days - one channel begins zu fade out.
First I thought, it was just a coincidence and two headphones were just broken in the same way (very low volume left channel). But than I bought original apple earpod headpones.

They worked great for two weeks.
Than the right channel faded out.
A day later the right channel was completely out.
This applied not only for the fp3 but for my laptop as well.

The next day, the headphones were working properly again on the computer. I connected them to the fp3 again. Both channel worked, after a couple of minutes the right one faded out, and than stopped working again on the phone and as well on the computer.
Another later the headphones worked again on the computer with both channels.

Now, I don`t dare to connect them to the phone again.

What could have happened here?
Does my fp3 destroy my headphones or initiate some kind of security shut off?

Did you upgrade your FP3 to android 10?