So the thermostat is in the hall, where the rad with no TRV is?
If your hallway is getting warm faster than the lounge, then the heating will turn off when the hall is ‘at temperature’ but the lounge is still warming up.
Probably not the ‘right’ way to go about it, but I would close the lockshield valve on the hallway radiator by 1/2 a turn and give it a day or two. If it is still too warm, give it another half turn.
This is what I’ve done in our house to try & stabilise the various rooms and it takes a while but does work.
If you google ‘balancing radiators’ you’ll find various guides to doing the whole house in one go.