Hahaha I'm telling you that the game is weird like that, even with all the catalogs on and even though almost every other enemy in the game will drop something no matter what while you have the catalogs on the Adamantortoises are weird. They have their own settings or something bc there were times when I got them to drop something almost every single fight for about an hour or two then they would just not drop anymore. Just keep it at, it's frustrating sometimes but def worth it.

If you need more of one item equip two of the same catalogs on two different characters. Last tip I always gave my characters some equipment that protected against Earth damage in some capacity which let me attack longer bc the ground attacks didn't sting as much.