S33 modem is 2.5gbps ethernet and TP-Link AX3000 is slower Gigabit ethernet ports max speed 940Mbps. If want all of that 1200 plan which is around 1440Mbps you need router with (2) 2.5gbps ethernet ports if want PC to get full speed also.

QNAP QHora-301W and Zyxel Armor have Mult Gigabit ports.

https://www.amazon.com/QNAP-QHora-301W-AX3600-Fanless-SD-WAN/dp/B08MQT9ZCX

https://www.amazon.com/Zyxel-Armor-12-Stream-Multi-Gigabit-Router/dp/B08K3GCBJM