Good to know. I had an issue where a 2024 expiring cert was used instead of the 2023 expiring one I had clearly specified at time of booking by cert # and expiry date and again when I asked to call to get it reticketed. I was repeatedly told it can't be fixed by too many DL agents to count, until finally escalated to CS and the third or fourth agent finally got it done (reopened the 2024 cert and closed the 2023 that should have been used). Took me close to 10 hours over two months to get that done, so knowing what an extreme ordeal it is, I presumed that it just can't be normally done. But seems like it's just another one of the countless of situations where DL agents will just flat out tell you lies, in order to get rid of you and get out of doing their job, or simply because they haven't been trained properly.