Comparing Data showing "Wrong" results.

Hi Everyone,

I have a weird problem in Excel that has stumped me now for 3 days! The attached file replicates the problem in a larger project I'm working on so hopefully illustrates this. So this is the scenario.

We have two lists going down column A showing years and months. Cell F8 basically uses a VLOOKUP on cells C2 and C17 to combine the two results into an output on F8.
If you then use a formula to extract the first and last words from F8 you get the results in F10 and F11 respectfully. Likewise I’ve used VLOOKUP to display the Month and Year in cells F13 and F14 respectfully.
Here’s the weird bit (weird to me). If I use an IF statement to compare if F10 and F13 are the same I get TRUE. However, if I use an IF statement to compare F11 and F14 I get FALSE!

I thought this might have something to do with formatting numbers/text in the cells but in the example file, the whole sheet has a General formatting applied.

Any ideas as to what is going on?

Many thanks in advance.