It was working fine and then just seemed to break. Below is my formula. I'm doing check for PTO which we maintain in a dif smartsheet.
=IF(OR(COUNTIFS({RDI Calendar Range 1}, [Assigned To]@row, {RDI Calendar Range 2}, >=Start@row, {RDI Calendar Range 3}, <=Finish@row) > 0, COUNTIFS({RDI Calendar Range 1}, [Assigned To]@row, {RDI Calendar Range 2}, <=Start@row, {RDI Calendar Range 3}, >=Finish@row) > 0), "Unavailable", "Available")