I had no problem with 2862, but just changed to 2865 and SKY Q stopped working, it finds the internet and then drops again.

I have my main SKY Q Box and the SKY Q 2nd Box LAN connected (Not WiFi), I have also turned off the Wifi mode of each SKY Q box in the 0001 Settings Menu.

My Internet connection is BT and I have manually set the DNS to 8.8.8.8 and 8.8.4.4

Each Sky Q Box I band to a specific LAN IP

On the Draytek router in the applications , i have the IGMP Proxy turned on for my WAN interface, but I have to turn off IGMP Snooping to fix the dropping issue, as soon as I turned off snooping, SKY Q box came up with its two little ticks and was stable, problem sorted.

Also

There is this guide , i was sent after questioning support on IGMP Snooping, who say turn it off on home network.

https://draytek.co.uk/support/guides/kb-igmp-proxy

My q box is hardwired to my 2860 (skk q wifi disabled from engineering menu). IGMP proxy, IGMP snooping, IGMP Fast Leaving options all selected. Q box is assigned it's own vlan and is the only device on that. All seems stable in terms of internet connectivity and connectivity to the router. On the latest firmware for the router and q box.