But you had to completely reinstall in order to that right? We have many users, so that is not feasible for us.
I was able to change the setting and did not have to reinstall - this might be something we can have our users change but I'm pretty sure this was caused by the latest update to Acrobat.
In Acrobat:
Click Edit and then Preferences
Check the "Show online storage when saving files" option - if there is a check mark clear it - then click OK at the bottom of the page
Close Acrobat
Open Acrobat and a PDF and then try to “save as” to see if you get the sign in prompt.

Not ideal but hopefully this helps someone.