Why does the Resource Management > Requirements > Status field show as Open for a Resource Type requirement in a report when enough hours have been allocated for that resource type to fulfill the requirement for that month?
The Resource Management > Requirements > Status field shows the status for the entire Resource Requirement type in the project; this includes all requirement hours for all months. If the Resource Requirement type has a requirement for another month that is unfulfilled, it will show as Open, regardless of if other resource month requirements are filled.
You can find the unfulfilled requirements in the Resource Plan for the project if you change the date to show previous months.
Fields from the Resource Management Date Groups folder (such as Resource Month) are not by default joined to the fields in the Resource Management > Requirements folder (such as Status), so you would need to create a Join in the report to have the Resource Month field successfully link to the resource type requirements by month.