I guess it may be because I've only had a US passport but have primarily taken Ryanair to fly between the UK (where I live) and elsewhere in Europe, which is potentially an edge case they don't care to handle well. I recently gained UK citizenship / a passport so perhaps this will get easier for me going forward.

Either way, I stand by my main complaint about Ryanair letting late arrivers jump the queue even if I only have to "suffer" from it when I'm checking bags.