Hi, thanks for your feedback!
I will look into the delay, munching shouldn't delay cursor moving too much, but when a lot of tiles on the board get updated it can.
Note that you do not refill the "stomach" / fullness bar when you eat a color Huey doesn't want. So for example, if you've completed blue already and you feed Huey blue, your bar won't get filled up. Hope that that explains it!