Missing Data

I see, that is strange

Looking at the bottom of your Power Query window, it does look like you have some blank rows. I don't see why this would be causing the issue you describe but it's worth sorting anyway. If possible, amend your Excel source to set the range of values as a Table (highlight the range that contains data then Insert > Table). Give the table a name to make it easier to spot in Power BI

When you import the data into Power BI, you will be able to select the Table definde above rather than importing the whole sheet. Hopefully this will be a bit cleaner and resolve your issue.

Another thing to double check if you haven't done already is that the data is genuinely missing - when you are in Power BI, sometimes the sort order will change so something that was at the bottom of Power Query isn't at the bottom when it's imported. 

If this post helps then please consider Accept it as the solution to help the other members find it more quickly.