I have created a number of InfoPath Filler Forms with associated SharePoint 2013 Workflows without any problem. I have one form and workflow though where the usual link to the associated InfoPath form is missing from the Related Items field in the Task Display Form.
However, I can use the Add Related Item link to insert the form link manually, which I don't understand because if I can navigate to the link why can't the workflow task.
I have noticed that it takes longer for the Workflow Task email longer to come through than those for any of the other workflows that I'm using. It's as if the workflow task is trying to find the associated form but can't.
I have compared the settings and configuration of the problematic task list against those that are working OK but I can't see any difference between them.
Your help or advice will be greatly appreciated.