AirPods Pro didn’t connect

I have a question about My AirPods Pro , so I was using them last night and fell asleep with one air pod on when I woke up I put it in the charging case . In 3 hours I went to put on my air pod but it didn’t connect . It shows that it’s there but when I take it out it goes blank ,does anyone know what might have caused this.

[Re-Titled by Moderator]