Statuses must be associated to types. When a type is chosen in a module, the statuses dropdown will be populated with that type's associated statuses. To associate custom statuses to types, click on the Settings icon in the main left vertical menu panel. Within the Settings screen, click on Types in the left column and click on the Task or Bug secondary menu. Click on the vertical three dot menu for the specific type and click Associate statuses. Select the statuses to be associated and click Add.
To remove or disassociate a status to a type, navigate back to the list of types in the settings screen. For the desired type, the custom statuses already associated to the type will appear under the Associated Statuses field. Click on the for an associated status to remove it.