CXone Studio ASSIGN and IF logic not triggering downstream actions

Running into a stubborn issue with a CXone Studio script where branching logic based on an ASSIGN action isn’t firing correctly. I’m trying to set a session variable isPremium based on a flag returned from a REST API call, then route the caller using an IF action.

The ASSIGN action looks like this:

{
 "variableName": "isPremium",
 "value": "${apiResponse.premiumStatus}"
}

Immediately after, I have an IF action checking if isPremium equals true. Even though the debug logs show apiResponse.premiumStatus returning true, the script always takes the false branch. I’ve tried changing the IF condition to check for the string "true" instead of a boolean, but no luck.

Is there a known issue with type coercion in Studio when passing JSON property values to session variables? Or am I missing a step to explicitly cast the value before the IF check?