Argument passed in must be a string of 24 hex characters – I think it is

The id that was passed in to my function was already an object ID in this case, so did not need a new ObjectID to be created from it.

When ObjectIDs are logged out to the console they appear as hex strings, rather than ObjectID("hexString"), so I thought I needed to convert it to do the find, but it was already in the format that I needed.