You don't need a VPN! I host an AdguardHome instance and just expose TCP/853. I put my domain name in the Private DNS settings of my Android and I get 24/7 adblocking without the hassle and battery drain of my Wireguard VPN (which I still use to access private stuff)
Right, my post wasn't to suggest my Adguard is open for everyone :)
1, it's bound to a particular subdomain (I'm sure you can figure that out) - And it's still the same IP so you'd have only gotten certificate mismatch warnings 2, it's behind a Firewall that only allows connections from the country I'm in - this is almost certainly what's stopped you being able to access the port.
If you meet those two criteria you'll be able to query it.
My point was it's quite easy to do this yourself though and then you don't need to bother with a VPN all the time, saving battery and the hassle of having to either a) Have it on all the time even when you're at home or b) Remembering to turn it on every time to leave home.
I tried setting your domain as my resolver but no luck sadly.
alex@thinkpad ~> kdig @muppetz.com +tls news.ycombinator.com
;; WARNING: connection timeout for 116.251.193.218@853(TLS)
;; ERROR: failed to query server muppetz.com@853(TCP)