I couldn't find the suggestion/bug report thread for current Stable Groupy (2.12) so I guess this will do.

I use Groupy with autogrouping on some applications (Inkscape, as an example), and used to have no problems with it, but with more recent versions of Groupy 2, whenever I create a new window (tab) for an application with auto grouping rules, when the window is maximized, it would create that window, and it will still be marked as if it's maximized (according to the middle button in the top right of the title bar), but it very clearly becomes unmaximized, the window covers Almost the entire screen but offset to the top left, the offset ranges from something like 6 pixels to 36.

To better understand the issue, here is a picture example, using MS Paint:

That said, in order not to fully put the blame on Groupy, I don't know when exactly in my Windows 11 installation something happened, but visibly it looks very clearly like the title bars on maximized windows are a lot shorter than they should be (look at screenshot above). When they're not maximized, they're normal size. Would anyone know what that could be? Because I do think that could be related to the issue.

Additionally I wanted to address if it would be possible to fix or work around another thing I've noticed, with a Windows Explorer replacement such as Directory Opus. It has its own tabs system, but I was wondering if I'd be able to use Groupy instead for it, as it allows opening multiple windows, and it would work, but in addition to the previous issue, the new tab would always be placed before the current one, instead of after. 

My Windows version is: Windows 11 23H2 Build 22631.3296 though this has been an issue for longer.