Esim installation issue

[Mckerr]

Hi - can anyone help please. I installed an esim to my iPhone 11. It is working ok. However, I wasn't receiving messages so I was looking at the settings. 

Not sure what I have done however I labelled the eSIM as 'Travel' and kept my original physics sim as 'Primary'. 

When I open 'mobile service' in settings, now all I see is 'travel' sim and another one labelled 'business'.  Even when I try to select Primary, it doesn't let me. 

I have no idea why the Primary sim option has dropped off. Can anyone help please?

thanks