Problem Changing Form Storage TO MailChimp

I am trying to add MailChimp as storage location for my form submissions. After selecting MailChimp and  choosing the Audience name, when I click save I get: "Saving Error: There was an error saving changes to your block."

NOTE:  this is not a "form submission error."  I am trying to add MailChimp as an additional storage location.  Currently, the submissions are saved to Google and SquareSpace.  (At some point last year, SquareSpace made itself a storage solution.)

I have 1) confirmed the list name, 2) disconnected and reconnected MailChimp, 3) selected and deselected "Double opt-in". 4) I disconnected Google as my storage location. 5) created a new/empty MailChimp audience to store the submissions in.

Is this happening because Squarespace is connected as a storage location?  If so, how do I turn it off?

Does anyone know what's causing this?

Same issue here, so I'm bumping this to the top to see if anyone has a solution?

I am having the same issue. Anyone with an answer or update?