migrating contacts from Android phone

A few days ago I took my SIM card out of my old Android and put it into a new iPhone 7. All my contacts were there and everything was looking good only today the only contacts I can find are the ones I have contacted while using the iPhone.

I put the SIM back in the old phone and the contacts still show show up there but when I put it back in the iPhone they still don't show up. I have tried going into setting to "import SIM contacts" but they are still not showing up.

Am I missing something obvious or is there a procedure I need to follow?