the way you are joining the tables.
jason brown is ID 6644
in the cleaning_team_shifts table, the cleaning team, only one in there is 10
LEFT OUTER JOIN cleaning_team_shifts ON serving_team.id = cleaning_team_shifts.cleaning_team_id
you are linking the cleaning_team_shifts.cleaning_team_id (10) to the serving_team.id column
in the serving team column, ID 10 is clerical
looks like your joins are not joining the correct columns for the resaults you are trying to get.