This has been an ongoing issue for years now.
My Samsung TV somehow forgets the HDMI source of several inputs and reverts back to "unknown". It removes them from the Home menu and so it requires re-adding them (and renaming) every time it randomly 'forgets' them.
This gets incredibly frustrating when having to frequently set them up with the smart remote so I can control the volume through my SONOS home theater system.
As far as I am aware this should be a software fix, and I've seen countless posts on this forum about this issue, so why is nothing being done about this?
We can confirm that your TV is on the latest software version. We would suggest carrying out a reset of the TV by firstly disconnecting all external sources, then go to Home > Settings > Support > Self Diagnosis > Reset > PIN. Please note, this will reset any settings that may have been adjusted on the TV and set them back to the factory default settings the TV came with.
After this, reconnect your external devices to see if this makes any difference.
If you're still having the same issue after a full reset of the TV, it may well be that the HDMI ports will require resetting, which will have to be done by our Support Team. You can contact them on 0333 000 0333, mentioning that we've suggest a reset of the HDMI ports, and they'll run through the process with you. If they're not able to fix this after the reset, they'll be able to advise on the next available options.