This article applies to:
Deco X90 V1 with firmware 1.1.0
After upgrading to firmware 1.1.0, there is a feature called “Network Optimization” in the Deco app. Under certain circumstances, clicking this button will cause the disappearance of the 5GHz-1 radio of the Deco X90. Therefore, wireless devices would be connected to the 2.4Ghz, the speed will tremendously decrease.
To recover this, we have to manually reboot the main Deco.
However, it will happen again once we click the Network Optimization button again.
This has been addressed, and it will be resolved with the new official firmware. Customers who encounter the speed decrease issue can now update your Deco X90 to the official firmware. Since the firmware release process is applied in sequence, currently it cannot be detected on the Deco APP or web UI online upgrade, you can download it manually from the TP-Link website then update.
1. The above new firmware could be updated through http://tplinkdeco.net, there is an upgrading instruction in the zip file.
2. Please check the firmware version in tplinkdeco.net or the Deco app after upgrading the new firmware, making sure all Deco units are properly upgraded. The new version should be 1.1.1 Build 20210720.
3. If the issue is not resolved with this new firmware, it is suggested to email email@example.com with the subject [Forum ID 271830] Deco X90 loses speed after clicking network optimization with the specific issue phenomenon, pictures and videos would be more helpful. The “Wi-Fi analyzer (open source)” app could show you the Wi-Fi radios around you.