For me on Windows 10 in the Discord App, there seems to be a bug with the Channel selection.
Once i scroll down to the bottom of the channel selection i cannot go up again.
I have tried using the Mousewheel aswell as the scrolling-bar but neither can get me back up.
This only occurs when I scroll all the way down, not when I scroll down partially.
Everytime this occurs I can not as a result access the channels above.
Restarting the app with ctrl+R works and going to another server and back also resets the state of the scroll. With another odd exception: when i scroll down on server X and go to server Y and do the same, then go back to server X it's still all the way down. If i now switch to Y again it's back up and switching to X now the scroll will also be at the top.
There's just something odd here, when you scroll down all the way in the channel section.