Comparator doesn't send correct redstone signal.

What I expected to happen was:
I expected the comparator to send correct redstone signal from a brewing stand.

What actually happened was:
(It's obvious) It doesn't send correct redstone signal DOWNWARDS.

Steps to Reproduce:
1. The signal strength is incorrect when it travels downwards while it's not when it travels at the same level or upwards.

More details in the screenshots.