Give this a try ..
1st.
You Need to check your WIFI settings and zigbee channel.
Setup your WIFI system to channel ( 1 ) on all routers and AP's and reboot router and AP's.
2nd
make sure / setup hub ZigBee to channel 20 with 8-12 power.
then power off the hub .. using the GUI - Settings / shut down for 3-15 min
3rd
once you have all that setup .. power up hub.
Will take some time for system to settle down and devices to re-join.
4th
You may have a bad / weird USB power brick / supply.
IF you can find / have a different one that is 2+ amps I would try a replace it with the old one!
5th
If you install this program / app it will help find your devices and sometimes
helps them re-join system, also will show what devices are and are not working.
If that all fails ask [ bobbyD ) to look at the system. Good Luck 
