Bought Rain-X Latitude blades, mount lock does not snap in..!

I just bought a pair of Rain-X Latitude, and read the universal mount instructions for the "J" arm found on my 2012 Taco (simple slip-on, lock)

Well the lock does not seem to want to catch, like there is too much metal on the arm or something. Grr...

Am I missing something?
I would hate to mess the blade mount by forcing it...

 

Double check your install. Something is bound up or not aligned.

Very hard to determine based on forum replies.

Remember: Force is an answer, it may not be the right answer.

 

Thanks.
Hard to tell, visually, the "universal" mount is a big blob of plastic.
It may be that the end of "J" does not get fully seated, making it stick enough to be in the way of the lock?

EDIT/ SOLVED! There is an intermediate inner click the has the be satisfied for the J to FULLY seat, allowing the lock in!