I have the Archer C8 and several iPads, an iMac, and apple laptop. I can get over 200 on my Comcast 200 service. As the WIFI distance increases, they do slow down and then drop. I did add an extender to cover area where WIFI was blocked. I found position of the router direction, antenna direction, and height does affect the coverage. Note generally that 2.4ghz has more distance and 5ghz is faster.

@ArcherC8 

 

I have wired extenders all over my house. Android devices work awesome. Apple devices connect and drop constantly. Download speed is awful. 

On those apple devices, check all those apps and turn off location, notifications, and background app refresh unless you need them. Most default as on.

@johngalt 

 

I would probably check which extender the devices are connecting to. If you have all your extenders the same network name, then they could be connecting to a extender or the router that is physically far away rather then the one up close.