@cdfdfireman 

Remove the TP-Link router and wire your computer using the same Ethernet cable that originally connected to the TP-Link, test to see if those speeds are good. Now swap the Ethernet cable with the one you used to connect to the TP-Link router to make sure that cable checks out.

Connect everything back, now log into the router and try disabling bandwidth control, and parental controls, and save. Now try the speed test while wired to the router. Wireless speeds are always subject to a variety of variables but wired should get you close, not exact what you get directly connected to the modem, but may 800 to a gig.