Moreover: on Android 11 Pixel 2 XL editing notifications from "Telegram" chat (sound, vibration etc.) does not make the differences in such notification settings on Android device settings. I have noticed it since latest December 2020 updates to Telegram. Please, give the users ability to use old-style notification settings on Android (or, even ability to make notifications simple (not conversations on Android 11).
I can also confirm that the issue seems to be solved 👌🏼 no more repeated deletion of notification channels, and settings for priority conversations and ignoring do not disturb are also not randomly reset anymore. Thank you for addressing this annoying problem!