Speed test from who?
I’ve got gigabit fiber from AT&T and Netflix’s site is the only one that can reliably shove a full gigabit at me. (Or ,rather the 940mbps, which is “gigabit” according to Ma Bell.)
Maybe try fast.com and see if you get different reported speeds?
Maybe the router is just too weak? Well, I used iperf3 between two desktops that are both hardwired in and I got ~940 “Mbits/sec”.
Also this doesn’t mean anything: switching is probably handled by an ASIC in the router, and routing is handled by the CPU to keep track of all the NAT table state stuff, so you 100% could have a device that’ll pass gigabit on the lan, and only 10mbps on the wan.
It’s repeatedly happened before; hell this would be the 3rd time this year (at least!).