@NDN How many Deco do you have? Are they are Deco M4? So the internet connection just stop working on http(s) protocol only, other wireless devices still work properly? Try to change the DNS server...

@JR4 Sorry for the inconvenience caused, we will do some troubleshooting and try to fix it. 1. What is the current network topology? How do you connect these devices together? Like modem--main...

@Petrinho Is there any error message pops up？ Try to disable 5GHz and enable 2.4GHz only to connect the TV to the Deco wifi network. Besides, you can enable guest network to give it a go. May it help.

@ScreenNameNL Thanks for your requesting; Cause the TV can connect to the wifi with fast roaming disabled, that is why we marked it as the best solution on another thread. Back to your case, we...

@danico I can get your point, while cause the repeater cannot detect the SSID with channel 13, you can give it a go by changing the wireless channel to 1 or 6/11 to verify whether it can be detected....

@Hany_Rezq If the computer and other router can get internet with the same DSL line, there may have something wrong of the TD-W8901N. You can contact the retailer or the local tech support to check...