I'll attach a video showing the issue. Essentially, sometimes there's a slight lag for when "balls" (300 bills) of cash is accepted into XXL counters, which can lead to them sliding off the counter instead of going into the input. In the provided video there's instances of the ball being accepted immediately as well as instances of the ball being momentarily "piled" on the XXL input for a moment before being accepted into the machine.
Version 1.3.0.541. No mods, no cheats, fully vanilla.