Just want to give a little update, wifi connection seems slows a lot, only at 3 Mbps. On iPad on the same connection speedtest shows normal fast speed.
1. Restarted modem and router, same result.
2. Turn off and turn on wifi on ZU, same result.
3. Forget wifi network, and reconnect, same result.
4. Almost give up with frustration.
5. Turn off phone and turn it back on, then finally the speed back to normal.
So at least on my phone, i think i need to restart my phone every other day to prevent the drop on wifi speed, but still need to see if it happens again in the next few days.