@Mattjtemp OK, so here is first recommendation: switch Deco mesh to Access Point mode. See Switching a Deco to Access Point (AP) Mode You should be able to do that, because you have router Huawei...

@ahmetm I have Deco M5 with firmware 1.6, and you have Deco E4 with firmware 1.6. According to TP-Link, firmware 1.6 supposed to have "Connection Preference" feature, but it appears E4 is one (of...

You do have M5s, that white LED color you've seen should have been yellow. It was a good suggestion to check if Main Deco overheats. That could have explained reboots. Deco logs are not very helpful...

@Mattjtemp I might be able to help you with troubleshooting, but first I have questions for you: 1. I have M5s, I have never seen white light on it. Are you sure you listed the right Deco model?...

@valiant3600 When you get WiFi connected devices from the company whose expertise is not networking connectivity, they may have WiFi code written by software developers long time ago and before WiFi...

@ahmetm Your Deco has firmware 1.6, just like mine. Still, there is a difference between your and mine screenshots: my has "Connection Preference" line. This is where one can configure where...