updateMany is always returning MatchedCount: 0

When I try the video practices always returns 0 in updateOne and upadteMany.
For example:

use movies

db.movieDetails.updateMany({
rated: null
}, {
$unset: {
rated: “”
}
})

Returns : { “acknowledged” : true, “matchedCount” : 0, “modifiedCount” : 0 }

What can I do?

Please make sure you are connected to correct DB
Try to find the count before running the update
Its says not matched means no records with the given condition