I agree that the dotted lines show a split in the work but this schedule has no work assignments. All the tasks have a task type of Fixed Duration and some show a split and some don’t. That’s what I’m trying to explain. Why some are split and some aren’t.
I agree with you and I would have set the type to Fixed Work or Fixed Units. I recommended using Fixed Work to the supplier. And yes it can be tricky making that sort of change. Another option is change the bar format setting to not show the dotted lines.