Duplicate section functionality is weird.

I have a set of tasks I do quarterly and I want to duplicate the section to move them forward from 2025 to 2026. I’m having a lot more trouble than I expected.

I select “Set new due dates for duplicated tasks,” but then in ONLY changes the dates on the tasks that are not marked complete for 2025. I don’t even know how to articulate what it’s doing with the other dates, but they appear to be set going backwards from my desired start date for the full set of tasks, where the first incomplete task gets the date I set, and the rest are dated backward from there??

I tried uncompleting the past tasks, and it created NEW tasks for next year then immediately marked them as the ones I’d just “uncompleted” as complete. So now I have to go back and re-complete the 2025 ones, and uncomplete the new 2026 ones???

Anyone have any ideas what’s going on?