Can't figure out why VLOOKUP returns incorrect values

[edeibold]

I'm trying to look up participants' first names based on their identifier (the data is confidential, so I redacted all the actual data here). Column A has the participant's ID. Col A is linked to Col C, which contains the actual data (I did this because VLOOKUP can only look right). Column B is the participant's first name. I'd like to return a first name (col B) based on participant ID (col A). The lookup value would be entered in C1. However, my formula returns incorrect values. For example, the for the lookup value in the green cell (A17), it returns the value in the purple cell (B12). I tried setting the range_lookup argument to FALSE, and that removed the offset for values close to the top of the table, but caused an NA error for those further down. I'm really at a loss here

 

[edeibold]

I think the issue was Excel prioritizing higher up partial matches over a lower down exact match. Apparently that's just how VLOOKUP works. And the NA error was because I forgot to extend the range to some of the data