Hi,
I noticed that on the error there appears to be some duplication protobuf type of [type.googleapis.com/type.googleapis.com/<domain-event>]. We’ve have seen that type of problem before when there’s reuse of metadata from the incoming event to the outgoing one. The advice would be to make sure you create a new object for the metadata as mentioned here by Johan.
I’m not sure if this would cause all the issues you mention but I believe fixing that and retrying might be a good start.