Thanks for your help @adib_rahmang and @david64  I worked out the cause - it is the SQM/QoS feature of the Ubiquiti Edgerouter. If I disable it, I get the full speed (100Mbps). Once I enable it, it reduces my speed (as it should). I've adjusted the SQM settings to match my connection.  Thanks again ... View more

Thanks @david64  Updated the MTU to 1480 - still only getting around 75Mbps. I conducted the TPG speedtests and it all seems pretty smooth (see screenshot). ... View more