eSIM and No Service

I ordered an O2 SIM with a German number as I moved here recently. My intention was to use this number as an eSIM so that I could keep my UK O2 SIM in my phone and have access to my UK number too. When I originally set up the German SIM, I had service and I did when I managed to activate my eSIM too. As soon as I put my UK SIM back into my phone, neither data plan had service. I then tried to put the German SIM back in my phone and now this is saying it doesn’t have service either. 

I don’t understand what I’ve done wrong. I’ve now ended up with two SIM cards showing me no service and an eSIM that is no longer working. I’ve restarted my phone multiple times and nothing changes.