Switched from EE but still showing new number instead of transferred number

Just recently signed up to iD mobile, switching from EE. Wanted to keep my number so went through the steps of transferring it over and I received a text today to say the switch had gone through. However I’ve just had a look on my device info on my Apple account and it’s still showing my new phone number for my new phone and my old number on my old phone. How do I go about changing this? Do I need to activate my SIM card? Should I have done that?  I’m receiving all messages and calls on my new phone and have signal. The new number is also showing on my ‘sign in & security’, how do I get rid of this and it’s obviously not being used now that I’ve transferred my old number across. TIA