I'am trying to use this formula to make it work

=ARRAYFORMULA(IF(ISDATE_STRICT(S2:S) ; (MATCH(MAX(AB2:AB),AB2:AB;0)-1) ; "" ))

If there is a date in Column "S" I want it to display the sum of the blanks that would appear if in Column "S" is text

=ARRAYFORMULA(IF(ISDATE_STRICT(S2:S) ; ArrayFormula(MATCH(FALSE ; ISBLANK(AB2:AB) ; 0)-1) ; "" ))

I've tried this one as well but I only get 0's as a result.

Any idea how I can make it work?

Here is the sample sheet.