Outlook Not Syncing with Exchange server due to Active Sync issue

Hello, 

I work for a MSP and two of our client started having the same issue in the past two days where Outlook client on iphone and Android devices are no longer able to sync new email with on prem exchange server.

we can find event ID 1040 and 2002 :

We think that a new version of Outlook has been released that issues a bug where ActiveSync session are closed prematurely by the Application causing syncing issue.
If we reinstall the application or remove/add the account the mails are loaded successfully but there are no update after the initial download.

Does anyone has similar issue ?

Thank you in advance,

Regards,