As you may already know, administrators were able to set an idle timeout setting for SharePoint Online (see https://blog.hametbenoit.info/2017/11/10/sharepoint-online-configure-idle-session-timeout/) and Exchange Online (see https://docs.microsoft.com/en-us/powershell/module/exchange/set-organizationconfig?view=exchange-ps#:~:text=Exchange%20Server%202019-,%2DActivityBasedAuthenticationTimeoutEnabled,-The%20ActivityBasedAuthenticationTimeoutEnabled%20parameter&WT.mc_id=M365-MVP-7836) for quite some time when users use the web browser to access the services.
This 2 options are independent with each other and configured by either the SharePoint or Exchange administrators which can lead to different timeout values.
Well, a new and global settings is now available at the Office 365 level – deployment in progress and expected to be completed by late August) – which will apply to both workloads and ultimately will replace these individual settings (not yet scheduled).
When you configure this new global timeout setting and you already had configured either both or one of the existing settings, the new global one will take precedence.
It is highly recommended to implement the idle timeout setting (no matter the option you choose) as it help protect your organization and data when users log on from unmanaged devices using a web browser.
Once available in your tenant, connect to your Office 365 administration portal (https://admin.microsoft.com/) and access the Settings\Org settings blade to access the Security and privacy tab; there you will find the Idle session timeout setting
