Hoppers won't collect items from Hopper Minecarts or in general on Barrels

I was trying to build a poorly built Redstone machine (cause I suck like that) so I could continuously listen to the new disc Tears, but found out Hopper Minecarts don’t empty their inventory to Hoppers, Barrels, and other Redstone container blocks. And Hoppers won’t collect an item if its on a Barrel. (Which is a very random and specific block.)