I'm not sure what stage it re-engages but it could be 1 of 3 things. If it was working fine before cleaning , check to make sure the ratchet on the driveshaft is seated , check the base of pinion gear, it wears where it set on spool shaft, & check the pinion yoke and see if it sets all the way down on the release on base of the frame.
I haven't repaired very many Curado's , but being a Shimano one of these is the fix.
David