Comment 27 for bug 1803993

As suggested in the freedesktop bug, this probably was fixed with the patch added for bug 1817738 which is this commit:
https://gitlab.freedesktop.org/plymouth/plymouth/-/commit/85d843af843589ce8538a59e5cb665b8253e380d

I haven't been able to reproduce this myself yet (when using the plymouth version previous to that fix), but I'll try a few more times next week.