After upgrading from postgresql 9.6, decoderbufs/debezium 0.7.5 to postgresql 12.3, decoderbufs/debezium 1.1.2.Final we began to notice data loss when the debezium process was restarted while a transaction was open. For example:

1. Start debezium process
2. Begin transaction T
3. Insert record A inside transaction T
4. Insert record X outside transaction T
5. Stop debezium process
6. Insert record B inside transaction T
7. Insert record Y outside transaction T
8. Start debezium process
9. Insert record C inside transaction T
10. Insert record Z outside transaction T
11. Commit transaction T
12. Observe that record A has been dropped from the CDC stream.

NOTE: `shouldMessageBeSkipped` method in `io.debezium.connector.postgresql.connection.AbstractMessageDecoder` will log and return true when it sees the message for record A.

NOTE: We’ve also been able to confirm that the bug was introduced sometime on or before decoderbufs/debezium 0.9.5.Final