motion 5 oscillate animated eyes blinking limit?

Why can't a 2 minute cartoon character piece only bling 4 times with the behavior parameter oscillate? I was able to duplicate the 2 blinks/oscillate layer for 2 more later blinks/oscillate layer. When I made a 3rd duplicate layer of the original layer for more blinks and no new animation appears in the Animated/keyframe editor window and the 2nd layer of blinks/oscillate vanished too!

Why does this occur?

I need my cartoon to blink more! \o/