AR no longer works on iPhone

Hello. For some reason, I can’t make my iPhone or iPad to work with the AR symbol anymore. It just keeps saying “Move iPhone to start” / “Continue to move iPhone”. But my scenes never turns up?
I deleted and reinstalled app on both devices, but that didn’t sort it.
Any suggestions?
Regards from Mikkel

try it again after a couple hours, move iPhone (if you didn’t), restart iPhone (turn off and back on).
that’s all I got for now good luck luv