https://bugs.winehq.org/show_bug.cgi?id=51316
--- Comment #2 from yuri6037@yuristudio.net --- (In reply to Zebediah Figura from comment #1)
Is this bug present in upstream (non-staging) wine?
I don't know, I've only tested under wine staging 6.11 as given in the latest APT repository.
In order to test on upstream I'd need to boot my VM which I currently don't have access to. I'll try tomorrow.
I'd expect the same if wine team didn't implement this function. EXCEL calls this everytime I press and release any of the corners to resize the user form.