the workflow is assigning tickets to user from the assignment group even through i didn't provide

[abhi1998]

the workflow is designed  to close sc task without the "assign_to" field is automatically populated even through we do not specify a value in the workflow upon reviewing the business rule i did not find anything related to this behavior.

one thing i noticed is that when i tried to close the ticket manually ,it promted me to provide a value for "assign_to" field becomes mandatory as well which is why it automatically assigns it to someone and close it. does workflow are able to close the ticketeven if the "assign_to"field is marked as mandatory while closing.

[Harish KM]

Hi @abhi1998 the workflow do not assign a value directly if you dint specify in your workflow to update assigned to.

Assigned to becomes mandatory during closure then there is some ui policy or client script setting it to mandatory but it cannot assign to some user, this happen is there is any assignment rule or business rule or client script at backend which sets the assigned to value. 

You need to look below things

Default value on assigned to field

Client script

Assignment rules