Add cellular plan missing

I upgraded from XS Max to iPhone 11 Pro Max. The add cellular plan menu is missing in this new phone but it existed in my previous phone.

Phone is purchased unlocked and without carrier affiliation from apple.com

I have two imeis in settings/about. I looked up imei number two which is a esim imei.

Now, I have factory reset the phone several times trying different physical sims, restoring iCloud backups and also restoring as a new device.

I have contacted apple support over chat and phone and keep getting passed around like a toy.

Several other posts in this forum about the exact same issue and not a single one got their problem solved. I would guess it is time to switch to android where we are not locked in a ridiculous ecosystem where freedom of choice and customisation is not a high priority and support is totally ignorant and unwilling to either replace phone or acknowledge some kind of bug.

So, is it time for me to switch to android at last or is there a real solution to this? With real solution I don't mean contact apple support or carrier as they are not doing ANYTHING about this issue.

This was no problem on xs max and both phones are running ios 13.5 and still xs max working fine and this ridiculously overpriced excuse for a phone do not have the one function I really need and was advertised of having.

Please, did ANYONE manage to resolve this issue?