Hi

We have a Vigor2860ac on the latest UK firmware (3.8.4.5_BT) and I have a MacBook Pro 2017 (latest OS 10.12.6, this also happened with 10.12.5) with 802.11ac wifi connected via 5GHz. The router is set up for channel 36 which has been identified as free (AP Discovery shows our old 802.11n Apple Airport on 44 and a neighbour's 3 BT networks on 40) and I've also tried various other channels.

I have found that quite frequently - especially when a lot of data is being transferred, for example downloading or copying a large file - the wifi tends to just stop communicating completely. It shows as still being connected but you cannot ping anything or contact the router's web interface. The only way to get data to flow again is to disconnect and reconnect.
I'm not sure it's always when a large amount of data is being transferred (it did it just now when I was typing this, unless something was happening in the background) but it usually is, and usually after 1-2GB.

Any idea if this is an Apple thing or a Draytek thing, or anything that can be changed in the settings to fix it?

If necessary I have the (huge, 224MB!) log files from Apple Wireless Diagnostics, which just returns generic advice about wifi channels etc.

Im having similar issues with my MacBook, I posted a call for help earlier. I know you said you changed channels but i noticed that you were on channel 36 and on checking so was my main router 2860AC so I changed it and strangely 5ghz came back on without the need to reboot. I will see how i get on over the next day or so (or maybe hours)

I set it back to auto and it picked channel 100 and has been fairly stable since, so no idea what was going on really. I do get what seem like DNS delays though - say when searching from the address bar in Safari it'll just sit there for like 5 seconds before loading which is really annoying. Actual sustained throughput is fine. Don't know if all these issues are Apple or Draytek, undoubtedly they'd both point at each other and say "it's their fault" but I can see that Apple Airport is going to be the way to properly connect this thing.

I have put a ticket in to technical so let see what they come back with. Its going to get to the point soon that I just send it all back, I was expecting big things from this kit.

Still having the same problem. Some days it seems worse than others, weirdly? Could be my usage patterns.
I was trying to browse while watching Youtube earlier and had the stalls happening every 15 minutes or so and having to toggle wifi off and on, it's really frustrating. Connected to an Apple Airport for now and it's fine but I was hoping to be able to use the Draytek considering it's a very expensive piece of kit (I'm trying to hold my frustration and not call it something else that rhymes with piece of kit) with 802.11ac..