Why is my scenario jumping routes during a cycle?

My scenario has a router that splits into two routes. One is the fallback (although having no fallback but mutually exclusive filters makes no difference). The routing is based on the existence of a form on a project. Two bundles travel through the scenario. The first bundle spots the form is in place and moves on to the end. The route includes a couple of text aggregators. The second bundle takes the same route because the form is in place (same project) and it runs the route it should but this time it also jumps onto the other route and runs one of the two text aggregators, skipping the first couple of modules on that alternate path. The second path has never fired so I cannot see why this should happen. I've attached a picture showing this. The scenario is trying to gather document approval details (approvers, statuses & dates) and paste the lot into a custom form on the project the tasks that hold the document being approved sit. Thanks v much