Why is this returning nil when casting to String:Any

Hi all. I've been looking at examples of using alamofire, json etc.

For a downloader I have a function that takes some parameters of String:Any

Then my view controller calls this function passing in parameters, uses almofire to retrieve the data, and returns "json"

Then in my view controller I have after that

guard let responseFromJson = json as? [String: Any] 

else { 
    print("Whatever message") 
    return 
}

This always goes to the else statement and responseFromJson is of value nil. I'm learning Swift and I'm a bit confused, because every other example I've seen online uses if not the same method, very similar and every question has answers saying the same.

My debugger says json is of type "Any?" with NSDictionaries in it, but the terminal tells me it's of NSArray with NSDictionaries. If I do

guard let responseFromJson = json as? NSArray

It's the only way I don't get a nil.

I've been at this for hours and I'm very lost.

Thanks

EDIT: Folks let this be a lesson on why not to program 12 hours straight. A few minutes after posting this and getting off, I realized "wait, I have an array of dictionaries, not a single dictionary". The solution is

guard let responseFromJson = json as? [[String: Any]]

Which is another way of saying Array<DictionaryString:Any>

Sorry everyone!