Pivot table sum-ing same record multiple times

Hi All, so I have a simple pivot table.

Fields are Work order number, posted period (date) submission type (customer, warranty, internal) and then Invoice hours.

For SOME months, the Internal number is way off. 6 months out of 28.

When I looked over the data, for some reason and hence this post, I cant figure out why on those 6 months, that the pivot table repeats the same work order number multiple times therefore skewing the numbers drastically.

Attached are the spread sheet, as well as the SQL for the query where the data is coming from. Can anyone point me in the right direction?

I attached the file.

Thanks