I am not sure if this is related or may help, but this has been an issue I have faced for years now.
The file explorer will not open a new tab while having the preview pane open and when certain file types are using the preview pane (.doc, .jpg, .png, etc.)
If I deselect the file to remove the preview, then I can create a new explorer tab.
I can also create a new tab with ctrl+n
This has been an issue with every version of Groupy I have used (currently v2.12). I also have Groupy on several computers and use Win10 and Win11 Pro, some old, some new, and this has occurred on every single version.
Hopefully, one day the bug will be fixed, but deselecting the file in the currently open window may bypass the new tab prevention.
Although, with file explorer tabs now being a native feature in Win11 this may be a moot point. (I still use Groupy for everything else and prefer it over Win11 tabs.)