Using a Vigor 2866ax I achieve about 800down / 800up Mbps to the internet (WAN2). Over wireless (any 5GHz channel, 80Mhz bandwidth) I achieve about 300down / 800up to the internet. File transfers across the LAN go at about 430Mbps as expected.

Is it expected that the download should be so much slower than upload? I've tried several devices and they are all the same.

Many thanks.

Chris

WiFi throughput always varies. Good performance depends on so many factors. I take it you're using Oooka's Speedtest to measure? This also varies from server to server particularly when testing a Gigabit WAN. Browser performance also plays a factor as does anything else using WiFi at the time of your testing.

Try using a tool like iperf3 for end to end testing.
Make sure no one else is on your WiFi or using the WAN too during the tests.
Turn on Hardware Acceleration for your Draytek
Turn off Data Monitor.
Disable WAN1 if you're not using it.

Also why is 430Mb/s expected for File Transfers? WiFi5 real world throughput can push data around faster than that. WiFi6 (aka 'ax') approaches Gbe.