iMessage & FaceTime number

Hi, I’ve just upgraded my work phone from android to iPhone11. I put a new SIM card in and then transferred my old number across via my network provider. The phone works great with my old number apart from when I use iMessage or FaceTime it still uses the number of the new SIM card and I cannot seem to change it so that my phone uses just the one number for everything.

i’ve looked on a the help section but every time I restart my phone it has the different number for iMessage and FaceTime - any ideas?