I did some tests the past couple of days/nights and can say the only times when the A14 overnight battery drain is close to A13 is when placing the phone in airplane mode. No other changes (location, home WiFi AP configuration, etc.) recently. I'm with Graphene OS's latest update. Tried disabling some IM apps (WhatsApp, Viber) - not much difference.
To summarize - with A14:
- 3% overnight drain with airplane mode on.
- 3-5% overnight drain with WiFi off, mobile data off.
- 10-15% overnight drain with WiFi on, mobile data off.
I was thinking about resetting the WiFi but a bit reluctant because it is tight with the Bluetooth which I'm not ready for now (Settings > System > Reset options > Reset Bluetooth and Wi-Fi).