When using a fill clock to run the command /replaceitem entity @p slot.hotbar.8 item I am unable to eat/drink item (when switched out for an actual item).
After the amount of time it takes to eat/drink the item, the animation stops, I continue to hold the item (as desired) but the sound and particles continue, I continue walking at the slowed speed, and my food bar and status effects are unchanged. Letting go of right click lets me continue without slow movement or sound/particles but I am unable to eat the item.

Is this caused by the game checking to see if the slot has changed from it's prior state after and not before the replace item command runs?