For most of my clients, things don't change drastically between years.  If you can get the 2019 data to show on the organizer, I would take that and run with it.  Most clients aren't going to catch the difference, but for those that do, explain that you upgraded your software to a new and improved product and the conversion from the old caused you some issues.  Or just include a little note with the organizer explaining that the conversion wasn't perfect, but the organizer should still be helpful for those using it.  It beats spending more hours fighting the software.