Nevermind. I’m an idiot, had my firewall considering my home network as public and high risk so it was blocking everything.
Edited: solved by common sense but thanks for the effort dbrisendine
Is this a Comcast supplied router or a personal one you supplied? Unless you need IPv6 for personal reasons, you could disable that part of the network protocol (How to disable IPv6 or its components in Windows - Microsoft Support).
The other part of this is that the ISP may have scanning to see if your assigned IP / DHCP address is still in use.
If the router has a NAT setting, do you know if that is enabled?