If the system is automatically dispatching to busy drivers, make sure that “Jobs when busy” under the “Auto dispatch” section is unchecked. With this option unchecked, the system will only dispatch a new job to a driver when the driver’s status is “available.”
This option can be found in “Settings - Dispatch - 2. Assignment,” here:
https://admin.taxicaller.net/admin/settings/dispatch.php#company_tab_assignment