Previously working INDEX MATCH formula now returns #VALUE when Re-entered

Hi All,

A previously working INDEX MATCH formula, which, as of one week after first entered, returns #VALUE! when re entered. The formula is meant to detect the first cell in an range with data and then match to the date for that particular column.

Formula: =INDEX($F$3:$BF$3,MATCH(1,IF(F10:BF10<>0,IF(F10:BF10<>"",1)),0))

The formula recalculates fine when the values are adjusted in the referenced cells, however I can no longer plug the formula into the same or different worksheets without it returning #VALUE!

Admittedly, I am not a well excel educated man. In my research I see that INDEX MATCH formulas are notoriously buggy. Its also worth noting that I have checked and my calculation settings are set to automatic. I've attached an example worksheet below. Does anyone happen to have an idea why my formulas are acting like this or have a work around. Any insight/help would be much appreciated.

Thank you.