Apparently, as of July 1st, Intuit removed the ability to import GoPayment transactions to QuickBooks Online. Today (at least that's when I received a copy) they issued an email saying that users would 'need to update their App to version 11.0 (or higher) to keep using some of the same features. The email went on to say that you could find out more at 'this website' (GoPayment Migration Update & FAQ) which (as of the time of publication of this article) showed it had been last updated on July 16 (2019). [Be aware: much of the information on that website is repeated several times. It seems that every time someone asked a question, the moderator responded by simply copying and pasting the entire FAQ over again as the answer.]
The email went on to explain that, "Transactions taken in your current version of GoPayment (blue) can no longer be synced with QuickBooks Online. If you don't update your app, you'll still be able to process payments and view past transactions. However, in order for Sales Receipt and payments on open invoices to automatically sync with QuickBooks, you'll need to install the update and confirm your switch to the new experience (green)."
Source: Intuit
GoPayment_Try-new-experience
Apparently some GoPayment users were given the opportunity to 'try the new experience' (shown above) prior to actually converting, but not every user, and the trial was available on a 'by invitation only' basis.
If you are a GoPayment user, you may have already received your copy of the official email advising you that you need to update your GoPayment App, if you haven't been on the look-out for it.