Hopper minecarts diagonal to others can sometimes pick up items

When you have a hopper minecart on a block, and another hopper minecart one block below and diagonal in the cardinal directions North and West, the hopper minecart will take items out of the minecart above. This does not happen when the minecart is in the East or South directions (as shown in the video provided). Note: I used a client to get the F3 menu, but reproducing the bug in a normal world without the client also produced the bug.z

Here is the link: https://youtu.be/837Ax8gDpdc