The first item is Living as Christians (Part 2). It should be Part 1. Without part 1 there is no heading for that meeting part, and then the times get off as well.
Make backup. (!! If not, don’t even proceed)
Doubleclick “Living as Christians (Part 2)” and change to “Living as Christians (part 1)”. That should at least in theory do the trick.
If the change doesn’t stick, click the plus sign and hopefully that will automatically be Part 1. Copy Theme/Source/Time from what is now Part 2, then delete Part 2 (minus sign)
Again do nothing without first backing up. There is no Undo-button!
Next time it is better to modify Part 1 and delete Part 2, rather than the other way round.
As a tip to developers: Maybe Part 1 can be made required/fixed/undeletable? If possible, it would probably help.