Index, Match formula returns #NA error if result is from an average formula.

I am using an average formula in several cells and then trying to use an "index match" formula to return a cells info from a matching value. Why will the formula return an error if the result is from using an average formula (see attachment) but works if I use a result that does not use an average formula (hard number)? If I reverse the index match formula, it also works.

G8 does not = EXACTLY 0.439
If you expand out the decimals beyond 3, you'll see G8 actually equals
0.4390909infinity0909

Change the average formula in G8 to
=ROUND(AVERAGE(G9:G11),3)