@Rosco5455 

Can you give us more details on this?  How are you testing this and what results are you getting? 

@Philbert 

I was comparing speed results compared to the main unit speed that is connected to the modem. 800 Mbps download and 500 upload approx. Phone 6 inches away from unit for testing.

Upstairs unit I was only receiving 100 mbps download and 140mbps upload. 

Felt that download should be higher in comparison to the upload.

Since this post I have brought a newer network switch capable of 1000mbps speeds as my house has Ethernet cables through out it in the walls.  The other two M5 units are now hard wired into the internet. Speeds are great. 814mbps Download and 524mbps upload.

Beforehand I did feel enabling ipv6 increase the speeds for me.

@Rosco5455 

Hey

If you are running over WiFi backhaul and the signal is less than optimal, then it is not unusual to have the upload speed match or exceed the download speed and think that is what happened here.  Never been quite sure why that was but seen it dozens of times! 

If you have cables ran then that should totally solve the issue for you, it might be worth setting your Deco into Access Point mode if you have them all cabled, would be quicker overall if that suits the setup you are going for