A department name spans three employee rows in one tall merged cell. On screen, its meaning seems obvious. After rearranging the records, that visual grouping may no longer explain which department belongs to each person. Before sorting, make the relationship explicit in the data.
Give each record its own fields
Work on a copy. Use one header row for the data, with a department value on every employee row where it is known. A large decorative heading can sit above the sortable range. It does not need to become part of the records.
For example, three rows for the Support department should each contain Support in the department column. After sorting by employee name, that relationship travels with each complete row. Select the whole data range when sorting, not just the column whose order you want to change.
Unmerging does not recover deleted values
Microsoft warns that merging retains one cell's content and deletes the other cells' contents. For left-to-right languages, the retained cell is the upper-left one. Unmerging restores separate cells; it does not reconstruct values discarded by an earlier merge or automatically fill every row with the group's label.
Inspect the resulting blanks and restore values only where the original source confirms them. Filling every blank from the row above can silently assign the wrong department when a group boundary is unclear.
Finally, sort the copy and compare several employee identifiers, names and departments with the source, including rows at group boundaries. If the relationships are uncertain, return to a reliable earlier version or source list. Moving individual cells until the sheet looks tidy is not a substitute for rebuilding the records correctly.