Ongoing iPhone issues post update (Cannot Verify Server Identity)

[Winston]

space-time wrote:
Only other thing I can think of is a hard reset - assuming not an iPhone X, hold the home and power keys down at the same time until the iPhone restarts.

good tip, and speaking about that, how do you do a hard reset on iPhone X?

Hard reset on iPhone X:

1. Press and quickly release volume up.
2. Press and quickly release volume down.
3. Press and hold power button until phone restarts.