Hi all, thanks in advance for you help,

First of all I have plusnet fibre with 5 deco m5's set as access points and all hard wired back to a switch then into the plusnet hub router.

Everything works fine but im having issues usually from teatime onwards and after speaking to plusnet Cust services and testing everything they advise using a better router.

so I though having about 20 items using the internet at peak time in this house I'd spend a bit and get a good one and went for an archer c5400.

not realising until it arrived it was only a router and not a modem I now have a Bt hg613 modem.

so set up now is Bt hg modem to

archer c5400 router to

deco m5 main unit to

8 way switch where all other room Ethernet cables come to.

each room has a deco to a switch with all users hard wired to the switch, 

the only items not hard wired are iPads and phone

so thats the set up, problem is everything connects fine when in original set up (plusnet hub)

when switched to archer router the router connects to the internet, I can use the router WiFi to connect but the decos don't connect to the archer router

strange thing in when I log in to tplink manager set up page it shows the decos in the network map, but when I go to deco app it says no internet connection.

I'm not super techy with all the settings and stuff so didn't want to alter anything to cause more problems, but noticed in the ip setting dns primary and secondary were different to what plusnet recommended, I did change these but made no difference.

any advice sett this up is much appreciate

I've also posted this in the deco section just in case this is the wrong place