Share your experience!
I've seen that issue when there's dust or grime around the magnetic connector or if you are playing games that drain your battery faster than it can recharge, that goes for other apps or even tethering.
Did you try to remove the device and put it back? I only use a magnetic cable for my Z1.
You should let a sony service examine your device.
The dokcing station worked fine in the first 2-3 weeks without this problem and the next test for me was to turn te smartphone off and try to charge it the result was : https://www.youtube.com/watch?v=rem9Oi4Wiiw
4-5 seconds charging this time with powerbutton and volume button option and in the first video it was from second to second with the charge (blink) problem..
I'm facing the same problem but with power cable. Working fine with magnetic charger. This happened only after i used magnetic charger for the first time.