Got a few good months out of my Nexus 5 but it's taken to blackscreening when moved away from ear during call or just when it feels like it in use (there's a pattern I expect but haven't spotted it yet).
Bought it from Warehouse Stationery ~ 6mo ago.
Factory reset, just kept on doing it. Leaving device alone for unspecified period and it resets OK.
Behaviour seems consistent with proximity sensor getting the wrong idea. Interested to know if anyone recognises behaviour and/or has experience of taking back to WSL for return/replace?