While the above is normally helpful, an actual item aimed at helping the skill up rates of Magic skill categories was actually found to not work with Summoning Magic (Limnus Earring), I wouldn't be surprised if the error causing that is also at play with skill up food. Pure conjecture but the fact that they are initiated via JA may be the cause as to why in game aides to skilling up Summoning Magic skill may not be working correctly. making an already long process even longer despite having the proper set up.