Upgraded to Motorola SB6141 but not seeing Premier speeds

I recently installed and activated a Motorola SB6141 cable modem to replace an old DOCSIS 2 modem. After installing the new modem, my download speeds have decreased but upload speeds have increased. My last speedtest showed 21 down and 12 up.  Signal levels all appear to be good.

I've seen in the forums that in many cases with Premier Cox has to update a service code when transitioning from a DOCSIS 2 modem to DOCSIS 3. Could someone from Cox help me out with that?