Ok I am assuming you put in ingredients without resting the machine I will require further testing from the game as I had the same problem but I think resetting the machine is working just fine just do it before you leave the room and especially before you put in more ingredients.
First Edit: after further testing I was wrong however I have a new theory you might only be able to use 1 recipe and make sure you do it in the exact same order as the first time as it wont work probably.
Second Edit: you don't have to do what is above and I am currently testing the First Edits truth
Third Edit: I have no idea I will continue testing
Fourth Edit: CHEESE IS CURSED
Final Edit: just confirmed the cheese is cursed and is the problem don't touch the cheese otherwise its fine at least with eggs oh yeah don't combine 2 of the same foods either as long as you follow the no cheese and no 2 same foods you can play the game normally.
Sorry Final Edit pt2: turns out its any meal which the dev has not put in the game yet so if I had to guess there is some sort of error going on in the background changing the slots system in how it works (I am guessing the code it may not be the case at all its just from what I understand from my very limited knowledge of coding) so stick to the posters recipes and it should work and yeah for you the dev I have a solution to said problem put something like food waste as lets say the name for any combination you have not put in the game yet or ever to prevent the mixer from coming up short of something to give out so that it is not endlessly loading trying to set off the mixer for something that does not exist again just a suggestion