When the analyst changes the category originally assigned to a ticket the existing service type remains, the expected behavior is that Service Desk cancel the existing service type and attach the new service type of the new category.
The issue is caused by having the same ranking for both service types. When the categories are changed the service types are also changed but this will only happen if the ranking is different, otherwise the existing service type an SLA will remain.
A trace to the spelsrvr can show this behavior:
spelsrvr 23412 TRACE sla.spl 1510 Two Service Types 400073 and 400219 have the same rank - using id field a tiebraker.
Service Desk 14.1 or above
In order to avoid this type of behavior, ensure that the rank for each service type is unique.
1. Go to the administration tab
2. navigate to Service Desk > Service Type
3. Select the service types with the issue and edit them ensuring that the 'Rank' field have different values.
Additional information about how to create SLAs and Service Types can be found in the link bellow.