I used a shear on a mushroom and the mushrooms drop of, but when i pick them up they are invisible in my hotbar and i cant craft with them...
i fixed the bug by changeing the line:
"spawn_items": [ "red_mushroom", "red_mushroom", "red_mushroom", "red_mushroom", "red_mushroom" ],
to:
"spawn_items":

{ "table": "loot_tables/entities/cow_shear.json" }

,

and then made a loot_table for cow_shear.json