Likely formatting issue when comparing dates using If statement

[Heritage_CCS]

Column S is a copy from another tab ( ='other tab'!s3)

As you can see, the result of the if statement is incorrect.... UNLESS I manually enter the date in column S. I suspect some type of formatting issue but am at a loss for what to try. 

[#2]

@Heritage_CCS 

The values in column B are right-aligned, suggesting that they are "real" dates.

The values in column S are left-aligned, suggesting that they are text values that look like dates.

Try this:

=IF(B3<>IFERROR(DATEVALUE(S3),0),"OFF","")

[#3]

@Hans Vogelaar THANK YOU so much...that resolved the issue.