idiom question

I’ve always heard (and said) the phrase as, “All of ** a ** sudden.” Lately, I’ve been hearing and reading instances of “All of ** the ** sudden.”

Is there such a thing as the “proper” way to phrase this, or is it merely a matter of preference?

I think it’s regional. I grew up with the sudden and had to get used to hearing a sudden.

Weird. I’ve never heard of “the sudden”. What’s a sudden anyway? says it’s “all of a sudden”.

If it takes a little longer, it’s “all of two suddens.”

I’ve heard (and read) it phrased as “All the sudden”, which invariably makes me cringe.

I have heard people refer to other people using “all of the sudden,” but have only heard, used and read “all of a sudden.” The definite article definitely frightens me.