Wither skeleton with a bow on a furnace minecart shoots burning arrows

I have summened a wither skeleton with a bow that is riding a furnace minecart and the wither skeleton shoots burning arrows despite the bow being unenchanted. The furnace minecart doesn't have coal. I used the command /summon furnace_minecart ~ ~ ~ {Passengers:[{id:"minecraft:wither_skeleton",HandItems:[

{id:"minecraft:bow",Count:1b}

,{}]}]}