item_show / bring_in will be deferred, if object is not resized properly.
the deferred call of item_show_region() is on the calc_job(),
after calculating proper object, pan size, but still item is not placed,
so target scrolling position is wrong while item_show_region().
move deferred call to group_calculate() to get correct item position,
after item_place() and group_item_place() were processed.
This patch is reported on @T7367.