Touch area for keyboard sidebar buttons, smaller than icons in landscape mode, on iPhone SE 2
This only applies to landscape mode, and doesn't happen on the iPad version. Found this one on the 2020 iPhone SE, running iOS 15.1.
Controls at the edges of the screen can be activated properly, except for the buttons on either side of the keyboard (in both piano keyboard and pad keyboard modes). These buttons can only be activated by tapping the "inner half" of them; the half closest to the center of the screen.
The one exception to this, is the "Toggle Piano Roll View" button, which does work properly. (The "Show/Hide Keyboard" button on the right side of the screen does exhibit this bug.)