Related Zulip discussion: https://debezium.zulipchat.com/#narrow/stream/302529-community-general/topic/Infrequent.20traffic.20MongoDB.20not.20streaming.20change.20events

Problematic code:
https://github.com/debezium/debezium/blob/main/debezium-connector-mongodb/src/main/java/io/debezium/connector/mongodb/ChangeStreamPipelineFactory.java#L119

return andFilters(
                dbFilters,
                orFilters(
                        includedSignalCollectionFilters,
                        collectionsFilters));

When database.include.list is specified together with signal collection the aggregation match filter above will match ONLY the signal collection.

The signal collection should be matched ALWAYS. Thus the filter should match even's if they are coming from the signal collection OR they match the combination of database and collection filter (that is the signal collection should not be considered part of the collection filters).

The correct code should look like this

return orFilters(
                includedSignalCollectionFilters,
                andFilters(
                        dbFilters,
                        collectionsFilters
                ));