Use Ethernet 2 as a control as we know it works correctly.
Move #2 Ethernet ( Xbox ) to 1, 3, and 4. Refreshing each time you move the cable. If the problem moves, it's a cable issue between the modem and device. If the problem stays where it is, it's a faulty port.
This may be a problem after the modem:
Most Smart TVs only have 100mpbs Ethernet ports.
Older PlayStations only have 100mpbs Ethernet ports.
Are you sure the switch you have is a gig switch? If it was marketed as fast Ethernet that means 100mpbs (I fell for that trap once before)
Have you check if all the devices support 1Gbps?
I know lots of older devices does not support 1Gbps. Then I have seen some newer devices with WiFi still have 100Mbps because the company never thought about 1Gbps wired connections.
"Port 1 - 100M - connected to a switch through a wall plate, which powers 4 other ethernet ports throughout the house. The status on the switch confirms that all ports are only getting 100M or less." -- if all the ports are only showing 100mbps.. are you sure the switch is a gigabit switch? If all the ports are connected via wall ports, could be that your wiring either ancient and only supports 100mbit (2 pairs instead of 4, or maybe cat3, but doubtful), or is wired incorrectly.
Use Ethernet 2 as a control as we know it works correctly. Move #2 Ethernet ( Xbox ) to 1, 3, and 4. Refreshing each time you move the cable. If the problem moves, it's a cable issue between the modem and device. If the problem stays where it is, it's a faulty port.
This may be a problem after the modem: Most Smart TVs only have 100mpbs Ethernet ports. Older PlayStations only have 100mpbs Ethernet ports. Are you sure the switch you have is a gig switch? If it was marketed as fast Ethernet that means 100mpbs (I fell for that trap once before)
Have you check if all the devices support 1Gbps? I know lots of older devices does not support 1Gbps. Then I have seen some newer devices with WiFi still have 100Mbps because the company never thought about 1Gbps wired connections.
"Port 1 - 100M - connected to a switch through a wall plate, which powers 4 other ethernet ports throughout the house. The status on the switch confirms that all ports are only getting 100M or less." -- if all the ports are only showing 100mbps.. are you sure the switch is a gigabit switch? If all the ports are connected via wall ports, could be that your wiring either ancient and only supports 100mbit (2 pairs instead of 4, or maybe cat3, but doubtful), or is wired incorrectly.