Why is it that I hear the left louder than the right one with all the headphones that I connect to the laptop?

Recently I hear with different headphones, which I connect to the laptop, the left louder than the right, although I have not adjusted anything. How to solve the problem or What is the possible cause?

I'm happy about every answer.

Ear problem? Put it the other way around?

Alternative: Wrong sound profile. For example, you have stereo, but 5.1 or so.

Third, balance has been adjusted.

No.

Control Panel → Hardware and Sound → Sound → Double-click on desired audio output device → Level → Balance

I would say that too

Thank you very much. In these settings I could solve the problem. Thank you all. But why did that change? Can that happen by itself?

No idea, never had that. Still nice that I could help ^^

Already tried the KHs upside down? So you can exclude a weakness of hearing.