Hello Richard,
So I went into 'Settings', 'Options', 'General Tab', 'Application',
'Style', and switched the spinbox there from 'Fusion' to 'gtk2', and
restarted QGIS.
Everything seems okay now and I can get back to work again as normal.
Thanks very much for your help.
All the best and regards
QGIS, in the end, delegates the creation of Tooltips and Menu's to the
Qt-Toolkit.
The Qt-Toolkit then has different implementations to actually draw those,
depending on your Operating System.
I'm not familiar with Ubuntu MATE, but maybe it's not fully supported by Qt? In
other Linux
Background: I have recently upgraded from Ubuntu 20.04 LTS (Focal), to
Ubuntu 22.04 (Jammy). QGIS was upgraded at the same time to 3.22 LTR
Białowieża. I think I may have had 3.16 LTR Hannover before that but I'm
not certain.
The Problem: I can only read either the drop down menus in QGIS or the
