IN light of the info you have provided, it would appear that it's due to the different versions. It's probably best running the Decos in Router mode for now, (If you're anything like me you probably...

One last question I am using V1 Deco BE85, are you on same or V2? As thats the only thing I can see is markedly different between our two networks. I just plugged in my Backup Router (Synology...

Does your router have wifi? If so can you test it? It's worth investigating the cabling between the old router and the Deco, is it at least Cat5E? Can you change the cabling to see if the speeds stay...

So the Deco app speed test shows that your getting the correct speed from your ISP Is this the same in both Router and AP mode? (My thinking is that it could be your router (when Deco is in AP mode)...

@Mishastr 1. What device are you using to run the test? are you using MLO and Wifi 7? 2. What happens if you connect to the 6GHz only network in terms of speed? (Just in case your device is only...

@Mishastr i have my BE85 in AP mode and have no issues with upload and download speeds, can I ask how you are measuring this? My network comprises UniFi Dream router 7 with 900Mbps (D) and 110 (U)...