Salesforce duration field blank

I have created a report in Salesforce (Case lifecycle report) and have brought it into Quicksight. My issue is that the duration field (which is a calculated field in the report) is showing as blank in Quicksight. Does anyone know what the issue here is?

I have also tried rather creating a duration field in Quicksight however, this is not possible with the dataset I have so I have had to stick to using the calculated field in the report.

@Megan - can you elaborate more on the problem, is the data acquired via saleforce connector, and QuickSight not able to resolve datatype and now showing right values?

Data is acquired through the Salesforce connector, however data appears for all other fields in the report besides the one I need which is duration - it is showing as blank in Quicksight but in the report in Salesforce the data is there.