AdGuard DNS not blocking ads on Firefox iOS on Streaming Community?

Hi everyone, I have an iPhone and I use AdGuard DNS (free profile, DNS-over-HTTPS via VPN mode) for system-wide ad blocking. It works great everywhere, except on one streaming site (one of those "clone" sites that constantly change domains).

What I've already tried:

\-AdGuard DNS in Native mode → no difference
\-Switched to VPN mode (the one that creates a local VPN profile) → no difference
\-Enabled Firefox iOS's native Ad Blocker (the new feature released in August) → Firefox reports "no trackers detected," but the ads are still there
\-Verified that the DNS profile is actually active under Settings → General → VPN & Device Management → it is active

My theory is that the site serves the ads as first-party "in-page" content (same domain, same IP), meaning a DNS blocker can't do anything because everything is coming from the same legitimate host.

Questions:

\-Is my technical assumption correct?
\-Is there any way to block this type of ad *inside* Firefox iOS, knowing it is WebKit-based and doesn't support extensions like Safari does?
\-Does anyone have direct experience with AdGuard Home or other self-hosted solutions that handle these scenarios better?

Thanks in advance, and sorry if I formulated the questions using AI ❤️