I had to purge and re-install grub2. This went well. But I can't find the "grub-theme-breeze" anymore. It doesn't seem to be in the repositories anymore. Am I doing something wrong?
B.t.w. I am using Neon 5.9 user edition.
Thanks, Pieter

There are some instructions on how to modify grub2 to use the breeze theme in the comments here: https://www.gnome-look.org/p/1000140/

Thank you for your answer. But I still don't understand why they removed the package grub-theme-breeze from the repositories.

You may find an answer from the Neon sub forum: viewforum.php?f=309

or/and

Neon bugs:
KDE bug: https://bugs.kde.org
=> Marked as a Neon bugs: https://bugs.kde.org/buglist.cgi?bug_st ... oduct=neon
==> Bug 377374 - package grub-theme-breeze absent in repository: https://bugs.kde.org/show_bug.cgi?id=377374

Thank you. As for the bug-report: I only just filed it myself.