Redstone dust on glass blocks

Hello Mojang,

I've noticed strange redstone dust/wire behaviour. Redstone signal can "climb" on glass block but it cannot go down on it. Please check screenshots for explicit description of the issue. (It's the same no matter if stained glass or not.)

I don't know if it's a recent bug since I couldn't find anything about it and that's first time I use glass block to support redstone wires. Also according to my information it's not a regular redstone behaviour.

Thanks for your support and great job.