@DiapDealer,
I'll take a peak at all instances of QMimeData in PageEdit and Sigil just to doublecheck. There are not that many.
Thanks!
Update:
I think what you are remembering is here:
https://github.com/Sigil-Ebook/Sigil/issues/320
but your fix was correct and limited to Linux, so I do not think this is related to this issue.