@VCL Thanks for your reply. I do find that you raised feedback email via the Deco app. Back to your case, cause we cannot figure it out, to fix it, our engineer will email you later. If you are...

@Oeti With main Deco connected to the ISP router only, please connect your computer to the Deco when the LED turns red and click here to check the IP and gateway. And please verify whether you can...

@FuntIzuma You are welcome, glad to hear that it works perfectly. Now you can enjoy the internet with the Deco network. If need more help, please feel free to contact us. Good day.

@Gerben You can follow the instruction below to install the old firmware via firmware recovery. https://community.tp-link.com/en/home/stories/detail/582 May it help and have a good day.

@Gerben Please draw a picture of the current network diagram. How do you connect these devices together? What is the model number of switch? With ISP router--main Deco--PC, please run a speed test...

@pl_svn Thanks for your reply. What is the current network diagram? How do you connect these devices together? When the speed from Deco drops down to 90Mbps, please connect your computer to the...