My TV won't connect to smartthings

Hi there, in 2018 I bought a Samsung 55" smart tv, it was amazing, connected to smartthings, alexa did magic tricks with it and everything. I moved house this year and I had issues with it connecting but never thought anything of it until now when ive just brought a new Samsung tv thats connected to smartthings straight away so 1 will connect but the original one won’t all of a sudden. Its the UE55NU7100 from 2018. Im driving myself nuts because I also have just brought a samsung dishwasher and in Feb im due for a phone upgrade…s9+ to a s21 ultra but this is really driving me crazy not being able to get smartthings to discover my “old” tv again when I never had any issues until I moved house. Its connected to the Internet aswell so its not that.