The Open Tickler Listing report will only display for Interactions that are Sts 'O' or 'P', are on an active account, have a staff selected, and have a Tickler action that is not null. A tickler with a null action will show up in the Open Tickler list for the user in TA, but will NOT show up in the Open Tickler Listing report. To make it appear, you must add an action to it in Account Diary Entry.