Wacom Grafik Tablet: Brush Color multiplies itself when painting over it

Hi everyone, I have a question about a technical problem and am really hoping someone has some advice for me.

- Windows 10
- Wacom Intuos S 
- PS 2022

I have the problem that when I paint in photoshop, the color multiplies itself when painting over it (so it gets darker and darker when I paint over it with the same pressure). I have been researching a lot, but can't really figure out what is causing this.

It's probably not a problem of the tablet or the pen, because in Corel Paint it works just fine. I also made sure I have the Brush mode to „normal“ and pen opacity control in the option bar is activated.

Here's what I tried out so far: I turned off Windosw Ink and I changed the settings of the Adobe settings (PSUserconfig). But it's still not working. I'm wondering if it has something to do with the option „Transfer“, since I can't turn it off (or rather it turns itself back on).

Does anyone know what could be causing this? I would be really thankful for any advice 😃