So I've got myself the S20 plus G9860 which I believe is the Hong Kong variant, 5G dual SIM etc.
I've noticed I don't have the option for 5G under connection settings.
I'm using EE and have a 5G plan in the UK
EE have dismissed me by saying it's the phone and it being a international model.
I also don't have the option for e-sim which again is very weird!