Replication is missing a specific set of rows on subscriber
The reason the round trip is not occurring is because your subscription from Server B to Server A has its @loopback_detection property set to TRUE, which is the default setting.

As we can see from sp_addsubscription, @loopback_detection specifies if the Distribution Agent sends transactions that originated at the Subscriber back to the Subscriber.  If set to true, the Distribution Agent does not send transactions that originated at the Subscriber back to the Subscriber.  If set to false, the Distribution Agent sends transactions that originated at the Subscriber back to the Subscriber.

I'm aware that the documentation states that this property is used with bidirectional transactional replication, however, I have reproduced your scenario and it appears to be being enforced with plain vanilla transactional replication as well.  Dropping the subscription and adding it back with @loopback_detection set to FALSE alleviated the problem and allowed for the round trips to occur.

Technically your topology can be considered Bidirectional Transactional Replication since both servers are publishing and subscribing to and from each other, even though the articles are different.

Keep in mind that you will need to drop and add the subscription back with @loopback_detection set to FALSE since sp_changesubscription does not allow you to change the @loopback_detection property on the fly.

I hope this helps.