Hi ,
We are having the exact same problem (since last week), and not solved yet.
The support hasn't provided a valid solution yet, but as a result of isolating the problem, there are some hints that can be guessed.
[What is done]
Even if I deleted the application item and re-registered as instructed on the screen, there was no effect.
Regeneration of binary did not change the phenomenon.
The transition from Xcode 12 to Xcode 13 (and rebuilding) did not change the phenomenon too.
As trial, uploaded almost the same binary as another AppStore's app (version 1.0), we were able to apply it normally! (for business reasons, we canceled it.)
And in each of the above, we received the emails of 'App Store Connect: Version ... has completed processing.' each time.
[The Clue]
So we think that the source codes and the configulation themselves (or the browser, or account information such as paid billing contracts) have no problem.
And the other app's input-fields on AppStore Connect were the copy of that of the product version. So we also think the error is not caused by the form-fields of AppStore Connect.