When you have a query parameter for an interaction, you have to type in the subject that shows up for the interaction and the interaction type, but you do not have the option to use a more foolproof identifier like ID. As a result, the subject text must match verbatim with what is on the record. If the subject of the action alert is particularly long, it might get truncated. Go to the interaction page of a constituent you know should be showing up and find the action alert response in question. Under subject, copy and paste the subject line from here even if it ends with "..." and is truncated. Use this as the subject line in your query and it will work as expected.