If you have action targeting enabled, it will always try to cast it on them (if it exists) and will always fail since it’s a hostile target, making the spell get stuck on the cursor.
the target prioritization of this spell is messed up. It goes something like:
action target>target>macro modifiers such as @mouseover.
For example if I try to cast it using mouseover or vuhdo on someone while targeting someone else, it will always cast on my target…
So you either need a macro like
/cleartarget
/cast [@vuhdo] Zen Pulse
Or go to vuhdo’s settings and enable “target unit”. This will hard target each player when you cast something on them. And ofc you need to disable action targeting for anything to work.