Actually I'm wondering if the issue is the cable from my ONT to my router, EdgeOS is showing eth0 is only connected at 100/full
Turns out it was the cables that connect the ONT to the router (ONT -> Wall Jacket -> Patch Panel -> Router). If I connect the ONT directly to the router I get a 1000/full connection.
Supported with a new speedtest result here.
Thank you for the help and apologies for not having my hardware sorted out ><