Mango Smart Router seriously slow WiFi speeds.

I have just received this device today. I have connected it to my isp routers LAN port 1 via cable and done all the basic setup as well as updating the firmware.

I then decided to run a speed test and was shocked by how reduced my speeds are by this device.

When connected directly to isp router I get between 600 and 700mbps but when using the mango I get a max of 60mbps.

This surely can be right?

I would appreciate if someone could help figure out why this is as if I can’t get a decent speed I’m gonna have to assume this thing is a piece of junk and send it back.

The mango offers only 100 Mbps ports. So the max speed will be below 100 Mbps (~12.5 MiB/s)
While using VPN this will drop to 45 Mbps (WireGuard) or 11 Mbps (OpenVPN)

The Wi-Fi is only capable of 300 Mbps max.