I have a vanilla hopper pointing into the back of a north facing limited spruce iron barrel IV with a base tier void upgrade set to void overflow, only work with automation, and with a blank block filter. Instead of the expected behavior of it voiding the items that have full stacks in its inventory the items are stuck in the hopper. If I replace the hopper with a modded equivalent (PNCR Omnidirectional hopper) the void upgrade works in the expected way

Images of issue mentioned

This was fixed some time ago