The Calendar doesn't update color for booking

1: When a customer uses "Blank Transfer" gateway, the system will default Order Status "on hold", so the calendar doesn't display color of the date booked and the other customers still can book that date.

If you still want the calendar to display color of the date booked when the order status is "on hold"( It means the other customers can't book that date ), you can add bellow code to functions.php file in theme.

add_filter( 'brw_list_order_status', function(){ return array( 'wc-completed', 'wc-processing', 'wc-on-hold' ); } );

2: If you want the calendar to display color of the date booked when the order status is only "Completed", you can add bellow code to functions.php file in theme.

add_filter( 'brw_list_order_status', function(){ return array( 'wc-completed' ); } );