So this is nearly a year old! Anyway, not sure if this will help anyone, but the HDMI names resetting only occurs when you unplug the HDMI cable from the TV or the device, then plug it back in.
For some reason, LG failed to incorporate any kind of proper SAVE function to the HDMI settings, resulting in everything being reset when a device is unplugged and plugged back it. I disabled the Auto Device Detect option, or whatever it was called, to see if that helped, but it didn't. The only thing it DID so was prevent the Picture Setting from resetting.
This is a major annoyance, as for some reason, this TV has excessive input lag when playing Forza Horizon 5 on an Xbox One X (and a Series X according to others) and this lag can only be removed by changing the Picture Setting to GAME or by changing the HDMI input icon to PC. Once you do either one of those, the lag is gone. And this only affects FH5, no other Xbox One game has this issue.
Apparently, you can prevent the HDMI name rest by having the TV in standby BEFORE you unplug anything, but I have yet to test this theory. Kind of pointless for LG to put a SAVE button there, when technically, it does anything BUT save.
This is the only stupid thing about this TV, which is otherwise the best TV I've owned. What a stupid problem. How do we tell LG??