Export for web changes the position of image

[jonalange.de]

The best way to explain this is to look at my screenshots I attached.

But a small description: 
I opened a simple image from lightroom in photoshop, made some small color changes (adjustments -> levels) and exported it for web (the "new" export as... version, not legacy). I noticed it after I put it on the website, the gap to the left is too small. In Photoshop its centered, but the exported version is alligned to the left.
You can also see this in the export preview.

How can this happen?

I already tried to convert it to an smartobeject and rasterize it (to prevent some smartobject errors). Same result.

Also, the workspace/ file is 500x500px so is the exported image (no transforming or anything in the export process).  

[jonalange.de]

Photoshop 2021 Version: 22.0.0

macOS: Catalina 10.15.7 (19H2)

[jonalange.de]

Little update: After I merged the layers and set it to background the export worked as it should. But this can't be the solution. It's clearly a bug.