On this class the Blood Arrow has a visual Bug, in this case its that you don't see wether this skill is active or not.
Here its on Walock/Scout : https://gyazo.com/1ebc9b2d51bfdeb3ee5e39f61aa44165
This is how it should look /looks on any other Scout: https://gyazo.com/a21c357aa2d6d866f2d8ee2314ca91c4
Greetings.