Physical eSIM & Physical Sim

I have a GL-X3000 that I have been running with a physical sim in the UK All works as expected.

I purchased a Simpoyo physical eSIM thinking I could add an estimated profile to it and then have two networks available and be able to failover from one to the other.

It seems you can only enable one at a time, if I enable sim1 physical then the eSIM management page disappears, if I enable sim2 physical eSIM then sim1 disappears.

do I need to change the setup or is this how it functions?

You can only failover between both SIM slots. So you can active the eSIM, configure it, and use it as cold-failover. See: Cellular - GL.iNet Router Docs 4