What's wrong with this FilterByFormula?

I’ve got an Airtable data source, that is set up and works correctly in Data Testing tab using a filterByFormula url parameter, but when recreated with an appgyver formula, it fails:

“SEARCH('” + pageVars.sessionCharacters[pageVars.character_pointer].Name + “’ {characterName})”

…through an Alert box, I know the page variables work correctly leading into the Get Record Collection node, so this formula would submit the same string as the (successful) Data Testing would: “SEARCH(‘John’, {characterName})”

I’ve tried to use Aittable’s API encoder, but that returns an error, so that can’t be it. What am I missing?