Hi,

I had this problem with my A6000. The contact manager was going very slow and my phone would, at times, not wake up from the sleep mode. This used to happen even when I get incoming calls.

I realized that the problem was happening particularly when I was connected to the Net and was using Whatsapp. After lots of hair splitting and frustration, thought of deleting the cache and data of Whatsapp. This worked !!! Phone works perfectly now.

Varkey