Teachers may notice different time measurements for an individual student on their Activity Overview Report versus their Individual Student Report. This is because the Activity Overview is specific to a class, and only includes learning time that students have accumulated since joining that class. Once a student joins a class, this measure will include time spent on all material, not only material that was specifically assigned in that class.
The Individual Student Report on the other hand, which is accessed by clicking on a student's name, includes learning minutes that the student acquired prior to joining. It is likely, then, that the Individual Student Report will show more minutes. Please note is that when filtering by content type, the learning and exercise minutes will not appear.
Students only have access to their Individual Student Report, and so this is the number that they will see as well, which may not align with the Activity Overview count.
It is important to note that the Activity Overview includes minutes spent on any topic--not only those spent on material in that class. In the Individual Student Report, you are able to filter by content and type of activity, as seen in the image above.