ive just upgraded from M200 to M350, and this morning I’m only getting just over 1mbs using cat 6 directly into my PC.
not had an issue with speed before the upgrade
not sure what the other 2 posts in the thread are about - confusing at best
log into hub3 - 192.168.0.1 [or 192.168.100.1 if in modem mode] - DON'T SIGN IN, click - click router status [centre of screen] - and post the downstream and upstream figures - to see those press on the grey buttons/boxes labeled - upstream - downstream - also post the config page
if its an earlier hub button is top right
its worth trying a reboot and/or a reset of the hub to see if that sorts it