Sorry for the late reply. The VLAN Tag was the solution! Here is a quick wrap up of everything:
A quick Google search told me that my ISP’s VLAN tag was “201”
I navigated to the following menu:
Router GUI/Advanced/Luci GUI/Network/Interfaces/LAN/Physical Settings
At the bottom of the page in the “Custom Interface” block, I typed in “eth0.201” (case sensitive. “Eth” does NOT work) and clicked “Save and Apply.” I then exited the Luci GUI and went back to my Router GUI. I don’t even think I had to restart the router. My ISP suddenly populated my IP address and now I am reaching speeds up to 700mbps over my 5G Wi-Fi network.
Thanks for everyone’s help!