I've moved to 4.1.001, a totally fresh start with no settings or plugin restores.
The OSD problem was caused by "Move Left/Right" set to 16 which was ok in 3.2.36, but shifts everything to the middle in 4.0/1....
I don't understand how it took a day for me to notice, as a reboot appeared to fix it the first time I saw it.
I've set/reset the front panel display brightness settings to see if that sorts out that issue.