npc.Interact with moving npc

[DaffyDubz 4]

So I've noticed a strange thing when trying to use npc.interact("Attack") if the npc is moving. The mouse moves to the npc, and follows the npc kind of spaz-like for a few seconds before either clicking it finally or giving up and finding another npc. This only happens maybe once out of 10 or 15 interacts, so it's not really a huge deal, but I was curious as to why this was happening?

Is there another built-in method in the API that can accomplish this a little smoother or am I using it incorrectly, or do I need to build a custom click function or something? My guess is my sleepuntil is causing issues? I'd assume the npc.intereact() would return false if it couldn't interact, but does it still move the mouse? (Side question, is the source for various methods like this available anywhere? The java docs don't really explain the details I need, even just sudo would be helpful so I can understand all of it's functionality, because it's obviously not just checking if the npc has an interact option, it's doing mouse movements and clicks, possibly reading the text in the upper-left when the mouse is hovering over the npc? Speaking of that, side side question, how can I read that text in the upper-left hand corner when mouse is hovering an object?)

NPC currentNpc = getNpcs().closest(FiterStuff...)

if(currentNpc != null && currentNpc.interact("Attack")) { 
	MethodProvider.sleepUntil(() -> getLocalPlayer().isInCombat() 
		|| getLocalPlayer().getInteractingCharacter() != null,     // this is ok, right? wait until something is interacting with us
		(long) Calculations.random(2500,4600)); 
}

Thanks in advanced!