OH boy a topic I can weigh in on. This happened on last trip, April 2021. My husband had a single dated ticket, and 3 undated one day tickets. Day 1-3 of trip went smoothly. Day 4? No valid ticket you say? How can that be??? Well, on day one, the single day that dated ticket ws valid, it pulled one of the undated tickets. It took guest services awhile to fix this. On the same trip, my son had a dated 4 day hopper, and a single old one day left on a non-expire pass from a long time ago. Again, it took that undated ticket first, then 3 days off the 4 day pass. Again, we had guest services put back a one day ticket, I called after we got back and I noticed he was short a ticket. That one day left on the 4 day was of course expiring. (I wasn't sure they could even help with this one, but they did!)
Lesson learned is to make sure they prioritize the tickets. It is annoying we cannot do this, and we cannot even check it ourselves. I often have various tickets on our names (retired CM). I now try to move those to a fake name on
MDE so they don't get pulled by mistake, but that would not have helped what happened with DH. I still question why it did not pull that dated ticket, that was only valid that one particular day and use it? Ugh.