Domain failed to load under mobile networks

I would just like to know if anyone else encountered this particular problem.

I am pretty sure this is not a Traccar issue and just some problem between my mobile ISP and DNS provider. This because I ran multiple tests on different networks and it only failed on a particular mobile network.

I am aware that it is very likely that this forum is not for this particular topic, I apologize, but I figure that in this community there is a high probability of someone else having this rare issue, and I would like some feedback if that's so.

I should also mention that this is not isolated to the Traccar Manager app and that is why I know it has something to do with the ISP / DNS provider.

Thanks

Is there any other information? Like what error you're getting?

The app only displays: Failed to fetch, just like when there is no network.

Side note: I have the intention of adding an alert dialog to the app specifically to display no connection to the internet, but I'm still thinking about the method.

Important note: Your demo servers work just fine, this only gives me trouble with mine.

What I know so far is that there is some kind of issue with the DNS proxy by Cloudfare. I found this article of someone having a somewhat similar issue https://community.cloudflare.com/t/failure-to-load-but-only-on-mobile-phones-over-mobile-networks-with-cloudflare-proxy/509377. Is not the exact same issue, but it's close. I checked on the server side to see if I noticed anything out of the ordinary on the Apache server logs, but there is simply no communication when that happens. If I simply disable the proxy on Cloudfare, everything works just fine.

I also noticed that after enabling the proxy again the IPv4 addresses that are assigned to the domain are fine, it works on the mobile network, but as soon as it adds the IPv6 addresses it's gone again.

What country are you in? I know CloudFlare proxy, especially the free one, is blocked in many places.

I'm in Mexico, so that could be it, I was not aware of that