Variables in slide titles and menu in SL 360

I thought I had found a smart way to use variables in KC and Exam slide titles.

For KCs, I created a variable called KCNumber. I set the initial value of KCNumber to 0, and put in a trigger to increase KCNumber by 1 when the Timeline started. I titled each KC slide like so:

Knowledge Check %KCNumber% 

So, if it were the 3rd KC, the title would display as Knowledge Check 3. My days of having to number KCs for individual modules and then changing them when all the modules were put together for a single SSO were over. Or so I thought.

Problem: it doesn't work in the menu. The titles still look like "Knowledge Check %KCNumber%." I reluctantly went back to the old way.

Any idea how I could have gotten the menu to show the KC slide titles correctly? I assume I have to change the trigger from "When Timeline starts," but I don't see anything better from the list.