Place mushroom into hands. Left click. Eating animation, sounds, and consume status wheel proceed as usual. Hunger level does not reduce. Can hold left click indefinitely and eating animation and sound will continue, but hunger does not reduce.

Hunger seemed to be accelerated in this build, or at least around the time that I experienced this bug. Ate mushroom (successfully I think), potato, and apple within the span of five minutes and without sprinting, hunger was back in the red.