Sorta. It's like NAT except it's at your carrier. Multiple customers share the same IP.
If an attack or abuse comes from a CG-NAT address they have to throttle the IP and all the customers behind it.
If it’s not a cgnat, your ISP could be throttling everyone that isn’t using a whitelisted site. Try using speedtest.net or fast.com just before streaming, and see if it fixes peacock.