iPhone 11 screen randomly & regularly going blank

my husband and I both have an iPhone 11. We can be in the middle of a call, an SMS or just scrolling content and it randomly (but quite regularly) just goes blank. Tapping the screen or pressing buttons does nothing, but it will reactivate itself randomly after a few seconds or sometimes after several minutes.

Is this a fault with this model? It’s weird that it’s happening to both of us.