Upgraded Cable Modem, not getting upload speeds advertised

I recently upgraded my cable modem from a Nighthawk CM1000 to a CM2000 to improve my upload speeds. According to my plan, I have up to 100Mbps upload speeds, but my router (TP Link Archer BE800) is indicating I am only getting 35Mbps, which is the same as with my CM1000 modem. How do I get enabled for my full upload speed?