since 8 years now! at least for me
https://ibb.co/wdFYsn5
got a new comp a few days ago, and it still appears there... obviously everything is fresh and clean installed
is there any way to avoid this? any way to reload that tab? its just a visual issue, you can still tab blindly through all materials but ofc you cant work like that
happened sometimes and was gone again when reloading the file but this time it became permanent