Dashboard charts reverts grouping from months to days

Hello all, I'm finding two situations in which the pivot charts and tables revert back from grouping months to days. This happens on all the pivot charts and tables. 1. When adding a new entry into the source data; 2. When deleting an entry by highlighting all fields and deleting. Any way to lock in the month grouping? See before and after screenshots, and I have added before and after workbooks as well.Before.JPGAfter.JPG

So I am totally novice in excel pivot charts. But I added a formula to your table that names the month. When I went change Data Source it made me disconnect the filter connections you had. So that is messed up. But does this work?

I'm not sure what steps you took but I added the new line to your source data table and refreshed and it worked correctly and maintained the grouping.