As part of the event subscriptions API, we can retrieve `eventMetadata`. Typically this is an object with a bunch of different IDs. We're wondering about `TRANSACTION_ID` in particular. `TRANSACTION_ID` is useful for tracking the event across multiple subscriptions, since it's related to the change itself. But, it isn't always included in `eventMetadata`! We've been unable to spot a pattern - INSERTs, UPDATEs, and DELETEs all only sometimes include transaction IDs in "eventMetadata".
Why is `TRANSACTION_ID` sometimes not included in the response?