Using a match expression in a trigger for a field type ObjectId

MongoDB Atlas Atlas Triggers & Functions
1

Hi, I’m trying to stop my trigger firing for all rows. The only field I can filter on is of type ObjectId and this does not work (the instance field is not being updated):

{
“fullDocumentBeforeChange.instance”: {
“$eq”: “67093fa6f17c49e7843ca174”
}
}
Neither does this:
{
“fullDocumentBeforeChange.instance”: “67093fa6f17c49e7843ca174”
}
Or this:
{
“fullDocument.instance”: “67093fa6f17c49e7843ca174”
}
I’m at the end of my tether!