The latest update, 20.06.5, over the weekend has fixed it for me (so no 55% promo screen and you can get into your account as normal).

However, when you go into settings, then subscription, it...

a) Still shows as Unknown, where it should show as Active.

b) When you click on subscription, rather than showing you details about your subscription, eg QuickBooks Online Plus, and the feature it comes with, it shows a page about a subscription you can buy, eg QuickBooks Simple Start £4.99 / month and at the top of the page it says Account Type Fetching Status....

So this is a much appreciated temporary fix, but the underlying cause that it doesn’t know what subscription you’ve got (as a wholesale bulling account) remains