@chaos0989 This is hardware issue, but you have nothing to lose other than your time, so here is the secret way to downgrade. Which could brick your Deco unit if done wrong. Follow firmware recovery...

@tarentaise I do share your feelings, and also XE75 firmware version number 1.1.8 hints at supporting the feature. TP-Link listed it as supported in firmware 1.1.* for X50/X55. Yet, if XE75 does not,...

@IYS Yes, there is confusion between WiFi protocol names/numbers and bands. This is how it works: WiFi 5 - runs on 5GHz WiFi 6 - runs on 5GHz WiFi6e - runs on 6GHz

@chaos0989 You quite obviously have defective Deco M5 unit. You did good investigation and troubleshooting, and everything points to one conclusion. If you can still return the set, you should do...

@tarentaise Not every Deco model supports bandwidth limit. I am not familiar with X75, but if it does, this is where it can be found. Schedule and bandwidth limit to guest network: under Deco App >...

@Miepasie There are no settings in Deco M5 to change channel width. Still, the Deco would not change channel width just because. It is possible your Deco nodes are not properly placed, or VR headset...