ipv6 prefix delegation length - only /64 for residential?

Hello

I have xfinity residential internet. I have both ipv4 and ipv6 turned on for my network and they both work fine - however, ipv6, I seem to be only getting /64 prefix delegation no matter what I set prefix delegation to. When I read around the Internet, it looks like xfinity does delegate /60 prefix for residential internet customers. Can someone confirm if xfinity residential delegates /60 prefix or does it delegate only /64 prefix?

Modem: MB8600

Router: Unifi Express Gateway