When using 'Merge Two Constituents', there is an issue if both Constituents had a Prospect Plan with steps. The target Constituent ends up merged with two different Prospect Plans, but the Plan from the Source Constituent has no steps.
We are currently evaluating this issue and will update this article when we have more information.
Steps to Duplicate
1) Create two Constituents. 2) For each Constituent, create a Prospect plan with steps. Mark one or more steps Complete. 3) Run the 'Merge Two Constituents' process. Actual Results: The Prospect Plan from the Source Constituent appears on the merged Constituent, but it just has the name without any steps. The plan appears on the Target Constituent's record, but it has no steps. The whole Details tab is blank.