Very slow Wifi speed on GL-AXT1800

GL-AXT1800
Firmware v4.6.8 release1

I am seeing very slow speeds for both 5 and 2.4 wifi. With a LAN connection I am seeing approx. 300mbs down and 30mbs up (Starlink) - but if connecting any device via a Wi-fi connection (5 or 2.4) then I can only get around 4.5mbs down and 5-6mbs up - which is unusable.

I have checked and do not have any overlapping wifi channels on both 5 and 2.4 - so clear.

I have reset the router to default, and setup - then tested without any additional changes or tweaks. It also runs very hot, though I see the fan by default does not kick in until 75deg.

Any ideas on what this could be? - other than sending back for a replacement.

With which device do you connect via Wi-Fi?