Slow speeds On Deco S4

[Ezuzu]

Due to the SuperHub 3, absolutely sucking with range. I've been advised I switch to the Deco S4, and putting the Hub3 into Modem mode, though I've been getting really terrible speeds with constant drop outs. Paying for 350M, getting barely 100mb. 

I'm not sure what to do, I've tried to get some answers from TP-Link, but no avail. 

I'd really appreciate it if anyone can help. 

Thanks

[JINNY2]

I have come to a conclusion that the S4 cant handle anything over WiFi to go above 500mb. You will only get maximum speeds via Ethernet.

They are on dual band so they use the same channel as wifi devices to backhaul to other nodes.

I would advise getting a netgear orbi (RBK50- cheapest i found),which is tri band to get maximum speeds as it has its own dedicated backhaul channel for each node.

Therefore you should see Wifi devices hit maximum speed
.