I don't think it's DNS. I mean I can access the files, they just wont show in boost, which leads me to believe that it's an app issue.
Besides on my previous phone I used quad9 over TLS, and on my current phone I use whatever I get through DHCP. So even if I'm using quad9 as the primary DNS on my home WLAN's DHCP (which I probably am), I still use my ISP's DNS while on 5G, and the problem persists there as well.