Hmm, this may be helpful, today i did the following:

- Updated carbon theme and used it.
- Updated array theme
- updated callnotify
- updated fennec nighty build
- updated healthcheck
- installed shaded chat theme

Also i recieved a call today but device hanged for like 10 seconds and couldn't answer, and he called like 4 times in a row but i don't hear him talking when i answer.

I think the strange behavior started after that.