Keeps on changing back to other input device

I sometimes use in-ear headphones with a built-in microphone.
So when I plug them in, I change the input device from "internal microphone" (Internes Mikrofon) to "handsfree microphone" (Mikrofon der Freisprecheinrichtung).
I use it in german, I don't know if these are the right words in the english version.

I plug it in, change it, close the window but then the microphone automatically changes back to the internal one.
The strange thing is, when I leave the window open for at while and then close it, it doesn't change back.

Here is a short video where you can see it:
[https://youtu.be/1KkeoVHxvf8](https://youtu.be/1KkeoVHxvf8)

The laptop I'm using:
Acer Predator Helios 300 PH317-52
[https://www.acer.com/ac/de/DE/content/predator-model/NH.Q3EEG.009](https://www.acer.com/ac/de/DE/content/predator-model/NH.Q3EEG.009)

Is someone else having that issue or is it just a strange bug that only appears on my device?

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