Wireless connection very slow on all devices. Getting about 75mbps down, upload speed 300mbps. Doing the diagnostic speed test the download speed 627mbps/upload 917mbps.
The WAC540 diagnostics speed is run on the AP, and runs (permitting the WAC540 isn't run as a Mesh satellite) on the wired connection.
Based on the results it looks like you run on some symmetric gigabit Internet connection - the numbers show that there must be other traffic especially on the download direction. Well possible there are other wireless clients using bandwidth also on the WAC540 - what can lead to the lower download speed.
Beyond, impossible to say more - lack of insight (wireless client, 2.4 GHz or 5 GHz usage, wireless settings, 80 or 160 MHz bandwidth on 5 GHz...). Be aware that the wireless numbers are always limited by the capabilities of the wireless clients.
