When time is entered in a timesheet against the same task of the same project in two different rows, a report would display the data of these two rows,  as a sum of the hours entered and not as separate hours for each row. This happens even when the Summary Options do not have SUM enabled in the grouping section of the report settings, for any of the fields. Hence a row level user defined field containing numbers (number format) is part of the row, then the report would sum up the values of the user defined fields as well.

Web TimeSheet reads the hours in both the rows as one, as they are associated to the same task.

Make use of user defined fields (text format) or enter unique comments for each row or each hourly entry.

Note: If the comments are not unique for the the two common rows, then the report would sum up the hours of the row data and also show the comment.