Do not disturb except for specific apps

[Knallbunt]

Hello everybody,
I love the "Do not disturb" mode, but I have one messaging app (Telegram) that is still ringing, even if I turn on the "Only important" option. It is OK if I turn on the complete silence option, but than I am not able to listen to music anymore.
How can I delete the exception for Telegram as being important? When going to Settings -> Apps -> Telegram, I can see under Notifications that "Do not disturb is deactivated".
I am currently running Android 7.0 on Security Patch from 1.2.2017 on Sony Xperia X Compact.
Thanks for your help!

[Jake-SonyXperia]

Hi @Knallbunt,

Welcome to the community,

This sounds like the Telegram application may not be allowing Disturb mode to function correctly. 

Honestly, this question may be better directed through to the creators of the Telegram app, it is possible they have not included coding to allow disturb functions or simply they won't allow it.

Let me know how you get on.