Fill Up copies the next non-null value upward into null cells. It is useful when an operational sheet places a team label on the final row of each section. Fill Down would borrow the previous section's label and attach records to the wrong team.
The direction describes where the value travels, not where the label appears. For a label below the records, choose Fill Up. A final blank with no later label stays null because Power Query has nothing to copy. That is a useful signal that a section label is missing.
Fill works on null values. A text file may contain empty text instead, so replace an empty string with null before filling that column. Don't fill every column just because one label column is sparse. Quantities and notes often have different meanings. Once the labels are restored, you can group by team and sum hours, keeping any unassigned work in a separate bucket.