Default Wireless charging stopped working

Does anyone else have this kind of trouble? Wireless charging just stopped working. I've tried with two chargers and no effect. Chargers can't be broken because they both charge my older Nexus 4 just fine. USB charging works just fine but I've kind of used to wireless and it drives me crazy since it doesn't work. I haven't dropped the phone or anything, I even replaced the back cover with new genuine OEM back cover since I thought that maybe the coils in back have been damaged or something.

Could it be software issue or what?