It will work on a simo fine.
It's an error in your account setup which, if O2 can't figure out, I suggest you cancel and go elsewhere, as someone else has done last week for the same issue.
I have no affiliation whatsoever with O2 or any subsidiary companies. Comments posted are entirely of my own opinion.
This is not Customer Service so we are unable to help with account specific issues.Currently using:
Pixel 7a (O2 & Lyca), One Plus 6 (Sfr), iPhone 12 Pro Max (Vodafone)