We are not experiencing this OnePlus 7 Pro shut down bug on neither of our review devices, and it seems to be an isolated issue, but if your OnePlus 7 Pro is shutting down, a fix should be on its way to address it.

The behavior is pretty self-explanatory, scary, and brutal. Some OnePlus 7 Pro devices are shutting down out of the blue, regardless if you are using them or not. The only way to restart the device is by pressing the power and volume up buttons simultaneously for a fastboot, as the power button fails to turn the phone on.

We are aware of this issue, and we will be issuing an update to address it — OnePlus

It seems like the issue is not hardware related as several OnePlus forum members managed to pin the issue down to a kernel problem.

Source: OnePlus forums (1), (2), (3), (4), (5)