I am using LO from Debian Repo.
Interesting is: If I do not start "Libreoffice" but "LO Writer" - iz starts. And if writer was started first, Libreoffice starts with its generic icon, too. As long as I do not poweroff and on PC. If I first start LO with "generic starter", error comes up again and then is present on single starters (writer, calc, presenter) too.
Very very strange.
As I do know now that I should not start generic starter first I do have a workaround and keep watching that. I am not sure if GUI (I am using KDE) does not have influence, too.
Best regards
DF8OE