Brush blend modes and smudge tool no longer functioning like before

Hi,

I was working on a painting in photoshop where I was using brushes (different blend modes of those brushes) and the smudge tool. However, at one point suddendly these blendmodes as well as the smudge tool stopped working.

I already tried to reset the tools, I restarted photoshop and my computer as well. I checked if it also affected other documents, which it does sadly.

I looked around but can't find anyone with similar issues or any fixes.

Does someone know how to fix this so I can continue painting.

Thank you in advance!