New screen recording function is not working on my iPhone SE

I've followed the instructions to record my screen or to share it with TeamViewer but nothing works :-(

I did a iCloud Backup of my iPhone and reset it completely. After restoring from backup, I have still the same error: when pressing on the record button in the control center, I see 3, 2, 1 and then nothing.

I've iOS 11 latest beta.