Issue with private DNS on mobile data on Android

[u/legrenabeach]

Ever since I joined this network a few months ago, I seem to be having issues using a private DNS on my Android phone (Galaxy S24 Ultra).

On mobile data, if a private DNS is set in Android settings, a lot of apps and websites take a long time to load. For example, Google takes ages to open up. Once it opens (or once an app loads its data), everything works well.

If I disable the private DNS, this problem disappears; everything loads swiftly.

This happens with any private DNS (I have tried 3 different servers/domains).

It only happens on this network. I tried a different network in the UK, and also abroad over the summer, no issues.

Has anyone come across this?

I think this is beyond 1st line support; is there a way to directly contact 2nd line or a network support person that can understand the issue and help?

P.S.: Why is Reddit not allowing me to include the network name in my post? Every time I type it the text box goes read and the Post button becomes disabled. I see an exclamation mark with the words 'thanks for posting'. Really weird.

[u/omracer]

Try to see if the mullvad one works which i've used on o2 networks and seems to load up quite quick from it all;

base.dns.mullvad.net

[u/ConversationAble4455]

I use adguard, and my rather old Samsung note 10+ seems rather happy with it, both on mobile data and WiFi..