I have just upgraded to an eSim Pay monthly with O2 and my UK number. I also have a US eSim and I thought/hoped that both would be active at the same time. But when I swich one on the other switches off. Is this how thwy are supposed to work. I wanted to received calls and texts on both numbers.
The US eSim also has a VOIP app with the US number on the phone that works fine but I cannou understand the Apple/O2 data plan switching. Can someone please explain.
There is an (old) guide here, see if it helps https://community.o2.co.uk/t5/How-to-Guides/iPhone-XS-XS-Max-XR-Dual-Sim-Guide/ba-p/1175893
apple had a good article here: https://support.apple.com/en-gb/HT209044
O2 Customer service staff could not help and I gave up talking to them. Apple customer services were much better and had all the answers. But as a third party eSim supplier is also involved It seems its up to the customer to join all the bits together. I gave up with O2 help as they really only know about physical sims, and unlocking phones, both not applicable in my use case with two suppliers and two phone numbers on one phone reliant upon eSim switching