Blocked Services - not working for Whatsapp/Facebook/Youtube etc. apps

[almostserious]

Problem/Motivation
When i block the services of Facebook, Whatsapp, Instagram, Youtube the apps on Android Phone still work fine.
The Websites are blocked, but the apps somehow circumvent this.

Expected behavior
If i block Netflix, the Netflix App does not work anymore. I would expect the same also for the other apps. Is there a way to make this work? Do i need to enable a specific setting for them?

[ameshkov]

@szolin please check this on some Android mobile. I suspect that these apps might be switching to some fallback DNS when they encounter an NXDOMAIN response. Maybe we should switch blocking_mode default value to null_ip if so.

[Snapy]

@ameshkov Indeed they use Google DNS (8.8.8.8 and 8.8.4.4) as fallback. Can confirm seeing some udp requests in AG for Android log.

[szolin]

• youtube app uses youtubei.googleapis.com. If we block it, the app stops working.
• whatsapp uses a sophisticated algorithm and it evades blocking anyway.
• instagram and facebook are blocked correctly.

[ghost]

* youtube app uses `youtubei.googleapis.com`.  If we block it, the app stops working.

* whatsapp uses a sophisticated algorithm and it evades blocking anyway.

* instagram and facebook are blocked correctly.

sorry for replying but shouldnt the youtube also be blocked on the mobile by blocking the domain u said if we turn on youtube blocking? Also the facebook also works on android now even when it is on :(
edit: Nevermind XD its working now after update