Network status disconnected

[davidpears]

I have this exact issue. 

Had a UK Sim (physical) in my Samsung Galaxy S21 FE, worked well. the min I added a US physical sim (Mint mobile) my UK sim just died. Even removing the Mint one and just resetting it back to just the original UK sim - I still can't get any cellular service, just wifi. 

My UK/EE it just shows a status as ''disconnected'

[bristolian]

Does this same SIM work OK in other devices? Do other SIMs work in this phone?

Have you tried swapping the 2 SIMs around between the 2 slots? That would prove whether your issues are SIM-specific or slot-specific