The first thing to check is whether this member of staff is current on ScholarPack. If you go to the staff member's profile, click on the cog next to their contract and check their school arrival date, it may be that the date has been incorrectly input. The member of staff needs to be a current staff member.
In the example below the member of staff School Arrival date has been entered as a future date, so just needs to be edited. Future staff do not appear in reports.
If a future School Arrival Date has been entered accidentally, the absence data will not appear in the report at Reporting > Reports > Staff (tab) > Absence.