[Bug] Resizing breaks layout, weird additional 1-line scroll

[piscopancer]

Code_nIdg4QCkeT.1.mp4

3 things i don't understand in this video

1. No matter vscode integrated terminal emulator or alacritty, I can always scroll 1 line up, as if the terminal is X+1 lines high while app running. why?
2. layout breaks when resizing
3. weird characters below