Photoshop "not enough room for tabs to dock" bug

I encountered a bug in Photoshop V26.5

We are usung an automated Sreen Capture to Photoshop script. It basically just takes a screenshot in another softeware and posts it into PS by the click of a button (with Python).

From PS version V26.5 it does give me the error message "Could not open "viewport_screenshot.tiff" because there isn't enough room to dock it on this monitor. Try turning off Open Documents as Tabs in the Workspace Preference panel."

However, this only happens for the 2nd sceenshot (which, by the script will overwrite the first). The first sceenshot after opening PS will always work fine - the second will give the error messeage (reproducable  100% of the time). And surely I also have enough room for tabs on this monitor still.

Downgrading to PS Version 26.4.1 fixed the issue, so there must be something wrong with V26.5.