That’s because level 5+ ones generally require a large group to spawn them, and thus the meteor gets ate away by people without magnet… Your best option is to join/make a hunt with people who have magnets or pay people to follow you to trigger meteors to fall, start the fight then instantly leave. This will kill the meteor and leave everything intact.
Am aware of this, but highly doubtful one will remain intact with a large group - but have seen ones intact in the past - hence offering a nice reward for discovery