On an iPhone 7 plus, I am running AppSheet 13.9 on iOS 13.6.
I can sign in using Google and access my apps as well as shared apps.
After I logout in AppSheet, I can see “Sign in with” and buttons for all providers : Google, Microsoft, Dropbox, Smartsheet, Apple, Box, and Salesforce. However, only the Google button works. All the other buttons flash briefly but do nothing.
When I was running AppSheet 12.8.1 on the same iPhone, I could sign in with Microsoft correctly. It stopped working when I updated to AppSheet 13.9 today. Also, I can sign in with Microsoft on AppSheet 13.9.1 on Android.