Excel "If" function working in only one row

[nanobi]

I set up an excel sheet with an IF function that only seems to work in one cell (M27) for the false results. I used the format paint brush to make sure that all the formatting is the same, but for some reason I can't get the other false statements to show an "O". The same formula (different variables) is used for the column L with no problems.

Any assistance is greatly appreciated.