@David-TP 

  @shkhoo 

this is the itermitent speed that i am receiving on the 1Gbps plan... from 9:00 am to 11:00 am ... I am getting speed above 900mbps... the speed comes down to less

than 100 mbps around 12:00 noon... If i reboot the DECO BE85... sometime i get back 900+ mbps... most of the time it can only gives less than 100 mbps

Did you test the speed of Deco BE85 via "Test internet Speed" on the Deco APP? ...yes tested speed on DECO app

Have you received any error notice on the Deco APP, such as "Abnormal WAN Speed"?.... No error notice

will try to set the QOS to 1000m/s upload/download.

  @shkhoo 

  @shkhoo 

i have configured the QOS to 1000 mbps upload/ 1000 mbps download. But after rebooting the router...  the speed still show less than 100 mbps.

  @shkhoo 

This is my fibre terninal unit from Huawei EchoLife Hg240H

  @shkhoo 

this is the DECO BE85 router firmware

  @shkhoo 

Dear David, thank you for the reply.... I have tried changing Cat6, Cat7 and Cat8 cable .. still connectiing to TP-Link Archer will always give me a speedtest result of 800 - 900 Mbps. But when connected to Deco Be85... I can get speed test of 800 - 900 Mbps for a few hours... and then the speed test falls down to 90 Mbps. When I reconnect back the TP-Link Archer after removing the Deco Be85... straight away I get speed test result of 900+ Mbps.