Not a bug, that’s how the apps are designed. If you look at the permissions the telegram app asks you can figure it out. Route audio, view wifi connection, pair with bluetooth devices. When you connect a bt speaker, the OS let’s these apps know there’s a device connected and the apps start. OS and the apps have no way of knowing what you want to do with a connected device.

-https://play.google.com/store/apps/details?id=com.hamsteroncoke.oxxo

-https://play.google.com/store/apps/details?id=com.esuli.it.CrisSpider

-https://play.google.com/store/apps/details?id=com.q42.ohhi

-https://play.google.com/store/apps/details?id=com.MagnusOlsson.LittleWhiteRocket

-https://play.google.com/store/apps/details?id=com.ustwo.monumentvalley

-https://play.google.com/store/apps/details?id=com.ustwo.monumentvalley2

-https://play.google.com/store/apps/details?id=com.hamsteroncoke.zenge

There was some news years back that compared data collection of apps on iOS (when Apple was taking measures to limit FB) and Reddit’s official app was found to be even worse than the FB app.