EX8000 Extender disconnecting

Hi everybody,

I have been having a problem with my extender disconnecting when QoS is active on my router. If I have QoS on after about a week of no issues my extender will randomly disconnect. The I fix the connection is restarting my router and the devices will be connected. again. If I do this eventually it comes down to restarting my router everyday. If I have QoS off my extenders network speed gets cut in half as compared to QoS being active, but My extender doesnt lose connection for a solid month. (still losing connection but its less frequent) 

Im wondering anyone esle is experincing the same issue with the same router and extender setup? I think it might be due to the fact that my router is a dual band and the extender is a tri band but im not sure. If anyone has some insight to what is going on or can help me figure it out that would be awesome.

More background info. I have about 25 devices on my network at any given moment (idling and active and hardlined). I have made sure to split the devices between 2.4 and the 5 ghz bands as to not further strain my setup. 

Internet provider is Spectrum at 400 Mbps 

Modem -Netgear CM1100
Router- NetGear R7000P

Extender- Netgear EX8000