i have an issue with my main deco x68. I had my nbn upgraded at the start of the year to 1000/50  it was working great, never any speed issues over wifi until about 2 months ago. Now suddenly the 5ghz network goes from 850mbs to 11mbs. I had a reboot schedule set for every night, but it keeps crashing. Yesterday I had to reboot the network 8 times. Once I reboot speed goes back to normal. I have 4 x68 in my network, I have changed my main router twice but always the same problem, with main deco. I only have about 15 wifi devices on my network but they all run on the 2.4ghz network. Another 8 devices are hardware and the speed never drops for these devices. What is weird is the upload speed normal stays the same around 50 and now 100 since the speed boost. I have tried eliminating all my devices from the network, 1 at a time to see if something was causing the speed drop or interference.  All my devices have been on the network for a fair amount of time and never had an issue until now. By process of elimination at the moment, I think it is the soundbars connection to the sub woofer maybe causing the issue but that's all I have at the moment but that's a bit of a long shot. I testing with soundbar and sub woofer switch off atm to see if speed drops.