Camera is being used by another application???

So I've had this problem for a while now. I have an iPhone 8, which is fairly new. However, after I've been on Face Time for over an hour, it says something along the lines of "this device is being used by another application." I've tried everything else that people have said to do such as shutting down my phone and disabling apps that require camera. However, nothing seems to work. I've read a post from about 5 years ago with the same problem saying that it was a bug, however, I believe it should have been fixed by now. Any other solutions?