Just had an odd one. I switched on from standby at about 1130 and shortly after changed to BBC News Channel ready for watching during our lunch.
I soon noticed that the volume bar on the right was huge and not correctly displaying the volume, although the sound did adjust. Also that the subtitles were missing.
We stuck with it through the 12 o'clock news, after which I took it back to standby and then on again. Instead of the normal start from standby it appeared to be a full start as if I had removed power, which I had not.
Anyway, on completion it now seems to be back to normal.
I checked the software version but it was unchanged at Jan 2021.
Not looking for help, just reporting what happened for info.