I'm not really sure what you are trying to achieve in this Microflow but I've noticed:
1) You retrieve PetitionList and iterate through these results, if a certain condition is met you remove something from the PetitionList –> this won't work. Don't change the list you are iterating on (no adds or deletes). If you want to return a filtered list either use the filter list action or create a new list and add the items that match your criteria to that list
2) The debugger shows that for your current iteration the association between Petition (the current iteration of PetitionList) does not have an association value for Petition_Single, which means if you retrieve via this association nothing will be found because the association has not been set (atleast for this current object). Setting this association has to happen somewhere else, you need to check if they are set properly.
Let me know if there is anything else you wish to clarify.
With kind regards,
Thanks for the feedback, I have updated my loop to your suggestion in 1). I am still confused about what you said in 2)
On my debugger, I am showing a value being set for the Petition_Single association, though I might still have it set up wrong or missing something. Thanks for help!