MongoDB where array is not empty doesn't work

I tried making a Question using a MongoDB source where a specific array-type field is not empty, and all results are returned, even where that field is empty. I'm using the cloud version of Metabase.

Troubleshooting info? Screenshots?

I'm not sure what to screenshot. To reproduce:

  1. connect a mongodb source
  2. choose a collection with an array field
  3. do a Count of all documents where that field Is Not Empty

what I get is that the count is just === the entire collection. If there's a Metabase staff I can provide the link to the specific collection/more details there.