Predecessor popup is no longer showing task names

I'm using the ABC Project Manager 4 in 1 app and made a change to the Task Name field which seems to have thrown off the list of predecessors. The field was a standard text field, but I changed it to a list. Now when I go to select a predecessor, all I see if the project name which is not helpful if there are already tasks created as there are multiple lines with just the project name and I'm not sure which one to choose.

I tried to see if there was an option in the predecessor field to select which field it should look to for the task name, but I can't find one.