Is there a glitch with dhalsims st.lp? Random counter hit?

Street Fighter V
1

It randomly let’s me counter hit…
https://youtu.be/Ugisme-O_4Q

2

The first active frame of Sim’s s.LP whiffs on grounded opponents.

3

Oh I didn’t know that.

Any reason why this sometimes works? Am I accidentally delaying my cr.mp or something?