Hey there, and welcome to Apple Support Communities cosimo37,
We appreciate you reaching out to us about this matter and are here to help. We would like to ask you a couple of questions in order to get a better understanding. First, what exact version of iPadOS are you currently using? We ask as the menus and options can change slightly between versions of the OS, and we want to make sure we provide the most accurate steps. You can locate this by going to Settings > General > About. Also, does this issue occur on any other devices? Finally, what is your Wi-Fi and or cellular connection strength when this happens? While you gather that information, we recommend checking out these steps on how to turn off and restart iMessages and see if that matches up on your side.
" Turn off and restart iMessage and FaceTime
- Go to Settings > Messages and turn off iMessage.
- Go to Settings > FaceTime and turn off FaceTime.
- Restart your device:
- Turn iMessage and FaceTime back on. "
For additional information, check out this link: If you can’t turn on or sign in to iMessage or FaceTime - Apple Support
We thank you for your answers, they will help guide us to the next troubleshooting step.
Kindest regards!