Completion popover shrinks as I scroll in it
Whenever I try to scroll through the completion suggestions with the arrow keys, the completion popover shrinks from the right edge. Sometimes this is only a few pixels at once, other times it's big jumps, rendering the completions useless because I can't even see them anymore by the time I find the one I need.
I'm using Builder 3.36 on Ubuntu 20.04. My project is a very simple GTK project in C using Meson.