Occasionally Workfront users will not have access to data in reports. This can happen with Hours reports as well as any other type data. in most cases, no data, or only some of the data shows for the limited access users.
This can be remediated by changing the, "Run this report with the Access Rights of" setting. This setting is found under, Report Actions> Edit > Report Settings > Run this report with the Access Rights of:
Changing this setting to any user that has access to the report data will allow all users to see the same values. This setting can also be used to limit rights to all users running the report so everyone sees the same values/data.