Both the WAN port and the 3 x LAN Ports on our NeXuX are 10/100/1000Mbps ports and if connected to another 1000Mbps wired Ethernet device will pass data at 1000Mbps (1Gb).
A wireless device on the network will not achieve anywhere near 1000Mbps and depending on whether you are using the 2.4GHz or 5GHz wireless network, will only achieve around 50Mbps to 150Mbps. Please note that wireless devices share the maximum bandwidth that the wireless technology supports, so more wireless devices = slower speeds.
Other issues that can affect wired transmission speeds are; quality and condition of the network cabling – best to use Cat6 cabling as although a Cat5e cable can support 1000Mbps, it lacks any redundancies in grounding, which is a common point of failure in network cables. Also if you have a network switch plugged in to the router to provide extra ethernet sockets and that is only 10/100 it will slow down all devices that are plugged in to it.
If you have any speed critical devices like Smart TVs, streaming devices, etc. I would recommend plugging these directly in to one of the 3x LAN sockets on the NeXuX using Cat6 cable and you should achieve maximum throughput of data, up to whatever speed the StarLink antenna can provide in that location/time period.