isearch-hide-immediately

isearch-hide-immediately is a variable defined in `isearch.el'.
Its value is

t

Documentation:
If non-nil, re-hide an invisible match right away.
This variable makes a difference when `search-invisible' is set to `open'.
If nil then do not re-hide opened invisible text when the match moves.
Whatever the value, all opened invisible text is hidden again after exiting
the search.

You can customize this variable.