@NeilBintcliffe Finally found the problem. It was a 1Gb switch splitter that needed powering down & resetting. After that full speed of the internet was achieved. 👍🏻

Hi, I am having a problem with my Deco M4 setup. The 1Gb ports will only pass 100mbps after the last update. I have checked all the cables & tried the setting QoS TO 1000mbps, turning UPNP, Sip off...