iphone not allowing number transfer

[Grace035]

My iphone isn't letting me click save for my old number in the Sky sim but it's been transfered

[twilight+princess]

Try the suggestions here:
https://helpforum.sky.com/t5/Sky-Mobile/number-won-t-change/td-p/5095478
When this happened to me I had to reset the network settings then it allowed me to enter the transferred number.