We can't tell - we don't have access to your data to check the code and work it out for you.
So, its going to be up to you.
Put a breakpoint on the first line in the function, and run your code through the debugger. Then look at your code, and at your data and work out what should happen manually. Then single step each line checking that what you expected to happen is exactly what did. When it isn't, that's when you have a problem, and you can back-track (or run it again and look more closely) to find out why.
Sorry, but we can't do that for you - time for you to learn a new (and very, very useful) skill: debugging!
Have a look at these, they may help you get started:
MS Excel 2013: VBA Debugging Introduction[
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Ways to Step Through Code in VBA[
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