Using If Action Blocks with RBS signal

Hello,

my simulation stop time is 100

I want to create an input signal whereby the first half of signal (t<=50) is RBS and the other half is zero.

However, when I use 'if block' and 'if action block', the centerpoint between two samples is shown in output rather than the value being constant for one sample (i.e. my signal changes from RBS to trangular wave).

What could be the issue? ThanksTo show issue, I am showing the two signals together under same random sequence.

This is inside the if action subsystem

This is the output