The drain is normal. The connection of 3G/4G (LTE) uses a lot of juice from the device. I have similair results in Stock Sony. The only thing you can do is use only 2G.. This is enough for whatsapp but not for facebook, xda and many others.
Yaay . Two year member!
Device sent away for repairs to my USB Connector Will be back in two weeks!
I do not respond on techmail via the PM! Esspecially questions that can be found on the forum! Use search!