External IPv4 address wrong for area. ISP or Modem?

[artwrangler]

Hi all, I have a Nighthawk CM 2000 connected to Xfinity. I live in Oregon and my IPv4 address is coming from New Jersey. This is playing havoc with my tv watching as apps think I'm on the east coast. Xfinity is getting nowhere and suggests it's the modem. I have no clue-can modem settings cause this situation? or is the IPv4 address served from Xfinity? thanks and sorry I don't know much about networking.

[plemans]

The ISP is the one who supplies the public ip address. and it can change dynamically. 

the modem doesn't control it at all. 

What router are you connecting it to? 

do you have IPv6 enabled on it? 

[artwrangler]

Connected to an eero mesh and yes it's connected to IPv6 as well

[plemans]

Are you using any vpn's or anything like that?

[artwrangler]

nope-not at the time