The latest version of the Skype for Business Mobile client on iOS (126.96.36.199) seems to have resolved the longstanding issue of the use of multi-factor authentication (MFA) with Exchange Online. This is where the SfB app would connect to the users’ mailbox and display Skype meetings. You would also get error messages saying the client could not connect to the server.
Before this client, the only way for the SfB Mobile app on iOS to work properly with users’ Office 365 Exchange Online mailboxes enabled with MFA was to use App Passwords. This wasn’t a great user experience and most users would not bother with it meaning their mobile app would not display calendar data.
As of the 188.8.131.52 SfB iOS client, it appears that all is working properly now. Users don’t have to use App Passwords on their iOS device and the client connects to their Exchange Online mailbox and shows their meeting data.
If you find that for users in this scenario, updating the client does not fix the issue, try uninstalling the SfB app and then going to the app store and installing the latest version. There is clearly something that is cached that may cause the client to not successfully connect to the users’ mailbox and display meeting info. I am seeing this about 40% of the time. Hopefully this gets resolved in later builds.
Note: It appears the latest Android SfB mobile app (version 184.108.40.206) has corrected the similar issue for users of Android devices.