iMessage will not activate after transferring (pac) number to ID

Hope some of this may help you- just resolved my FaceTime /iMessage activation problem yesterday:

After switching to iD and following as much as I was able to (with an eSIM not a physical sim) of the advice on community, iMessage and FaceTime still had activation errors.
I had ported my number from O2.

Some details of what I encountered-

Settings >Apple id >Sign-In & Security

Phone number- was marked as unavailable for iMessage and FaceTime with an info button stating- 'You must have a SIM associated with an Apple device for +447xxxxxxxxxx to be used for iMessage and FaceTime'

I deleted this number which could be done as it wasn't registered. 

Resetting Network Settings on my iPhone did not resolve the problem.

My number was correctly showing in Settings>Phone
Erasing and inputting it again did not resolve.

I contacted live chat requesting a new eSIM and they were very helpful and quickly emailed out a new one. 

I then again attempted to follow the community advice 'How do I fix iMessage or FaceTime issues after I switched?'

I was unable to untick my Apple id email in Settings>iMessage and also in Settings>Facetime. 

I had to put my old O2 sim back in which allowed me to do that. 

I deleted my original eSIM

This then cleared my phone number in Setting>Phone

I then followed step 4 in 'How do I fix iMessage or FaceTime issues after I switched?' And waited 30 mins while connected to WiFi. 

I then downloaded my new eSIM and waited for it to activate and connect. 

Following successful connection, Settings>Apple id>Sign-In & Security showed my number again.

I followed step 5 and it worked perfectly, activating in seconds- iMessage and FaceTime work flawlessly with my mobile number now. 

I spent 2 days very frustrated trying to sort this out. I hope this helps someone to resolve a similar issue more quickly.

Having an eSIM did make this more difficult to resolve as I had to delete the old one and request a new one, as opposed to being able to remove the physical SIM card from my phone but it is now resolved without having to wait for a physical SIM card to arrive.