Originally Posted by SDQBound

Yes, when connecting on separate tickets. For example, I had two separate tickets, and checked in for both before going to the airport. At IAD, the agent had to make some calls to get me unchecked from the connecting flight so that the baggage could be tagged all the way. Same thing also happened many years ago and I thought it was a glitch at that moment, but it seems that they are not able to do so when the second segment status is checked in.

And yes, the first time I was advised to check-in immediately after dropping the bag to ensure my bag could be loaded in the second segment. The second time, the agent at IAD was nice enough to check me in and print my BP for the second segment.