I've noticed that when creating checklists, doing it from the Set Up menu, it does not allow you to sort them if you need to add more items to checklists. Also, once the checklists are in individual tickets, the tickets automatically rearrange the order the checklist is in. I reached out to SolarWinds help and they confirmed this is a flaw and noted it should be submitted here as a Feature Request and to note the flaw.