Why is headset with one button cause phone to do random things?

[Javonski]

Randomly, my phone started doing weird things when my headset is plugged in. It has never done this before. I have a feeling that this started when I Assigned Buttons that was meant for 3-buttoned headset on to mine with one button.
Every time I set it to control music playback, it randomly plays different music from my music app. And when I set it to control volume level, the volume goes crazy. But I tried headphones with no buttons at all and it doesn't do crazy things.
I have MIUI 11.0.5 and I've tried searching for this problem but I couldn't find a solution. Is there, like, a way to reset the settings for the assigned buttons?
Also, let me ask this, why doesn't my settings doesn't have options for one buttoned headset?

 

[ni6hant]

Randomly, my phone started doing weird things when my headset is plugged in. It has never done this before. I have a feeling that this started when I Assigned Buttons that was meant for 3-buttoned headset on to mine with one button.
Every time I set it to control music playback, it randomly plays different music from my music app. And when I set it to control volume level, the volume goes crazy. But I tried headphones with no buttons at all and it doesn't do crazy things.
I have MIUI 11.0.5 and I've tried searching for this problem but I couldn't find a solution. Is there, like, a way to reset the settings for the assigned buttons?
Also, let me ask this, why doesn't my settings doesn't have options for one buttoned headset?

I had the same issue. Turned out it was the issue with the headphone buttons. I just claimed money for the headphones and got refunded in full. If your headphones have warranty, claim it. If not, then there is just one thing you can do, put feviquick on the heaphone button so it can't be pressed at all.
P.S: It might even make the headphones unusable. Proceed with caution.