How to force Simulink D-FF become vectorized?

I'm trying to implement this D-FF based phase detector (PD) for my project.

The PFD needs to be implemented 15 times. the input clock (CLK) is a vector of 15, but for some reason, DFF 2,4 are only implemented 1 time.

How can I force it to be implemented 15 times?

Here, the output dimension is 1.