this is a strange one, as the CLI (what shows your number) should be witheld by the person making the call, not hidden or cloaked by the person receiving it
not sure how it works.
its handy to divert any witheld numbers from my contract phone to my payg sim, it shows up the numbers.
handy if your getting prank callers.
its actually the network that handles CLI, it differes between networks, which is why it doesnt always work same way.
If it moves about with the sim, then it definitely isnt a magic phone.
I doesn't make sense?...when you divert a call from your contract to your payg phone...surely it's your contract phone calling your payg phone....!!.....the 3rd party number irrelevant!