Debug.DrawRay Inconsistency

I cannot understand why this works:

Debug.DrawRay(transform.position,transform.up*10.0);

I change it to this with no other changes at all and it stops working:

Debug.DrawRay(transform.position,transform.forward*10.0);

Any clues? All I’ve done is substituted “forward” for “up”.

So while thinking about other inexplicable events I’ve encountered I decided to check whether “Collapse” was active in the console. Sure enough, turned that off and there’s my ray. Strangely though, it is now working regardless of the condition of the “Collapse” switch and it doesn’t explain why the “up” version was working. I don’t care, it’s all working now.

Question previously solved. [Adding this answer to remove it from the Unanswered list.]