The dimension doesn't tell anything about your tv that has a model code you should know what you describe with very few words is quite strange and the only think I can guess is your remote having some button blocked....
I can be sitting watching a movie on Film4 then the tv just randomly jumps through all the television stations and stops at channel 701 for instance then iv got to turn the tv back to the channel i was watching
Yes iv done both i even purchased a new remote it’s definitely not that + it’s been rebooted afew times the tv is only 3/4yrs but i think at over 3grand it should last longer than that.
