@Mhairitiree
Not really strange. It would seem to indicate that it is the TV at fault.
With two identical TVs, I would guess you must have two identical remotes. Assuming they are not individually paired each with its particular set, I would predict that both remotes will work one of the TVs, and neither will work the one you are having issues with.
As @LightFoot suggests, this could be a problem with the sensor on the TV that receives the signal from the remote; or it could be something deeper inside the set.
So first make sure the sensor is clean and not masked by anything in its way. And if that doesn’t solve it, you could try powering it off for a couple of minutes (buttons on the back of the TV and unplug it from the mains) and powering on again. Next up, if the remote still isn’t controlling it, a factory reset, which can be done again from the buttons on the back; look up in the manual which ones to press, in what sequence.
My favourite bedtime reading is a Sony product manual…
