@SeoulGal Most of the issues you described are because your Deco M9 Plus have very old firmware. It is so old, it can't be updated through Deco app. It has to be updated manually. Follow Method 3...

RBZ5416 wrote @Alexandre. Quote from @David-TP in the thread linked above: The 5GHz channel appears to be configured based on the region the device was manufactured for use in and they are apparently...

RBZ5416 wrote @Wrayman In fact I believe it was that thread where it was confirmed by TP-Link that the 5GHz channel is stuck on 36 regardless of how congested it is. @RBZ5416 This is not correct...

@samclark24 Usually, you do not need to start from scratch while replacing ISP Router, with Deco mesh in Access Point mode. I went through two ISP Routers while I had Deco mesh. Mine runs in AP mode....

@Whitesnake DIsable dual-band for Deco Main Network and see if it makes the difference. This is the setting:

@AlbertH999 These speed test results mean, you have Internet link with 900Mbps download and 100Mbps upload. Deco M9 Plus is WiFi5, it can't deliver these fast speeds. If you want to hit gigabit...