This has been happening for about a last month with some of our Samsung devices that have email deployed via our Sophos Mobile Control on prem server.
These devices change their Active Sync Server configuration address. They change from what is configured in Sophos Mobile control to an address that doesn't connect via Sophos. This then disconnects them from their mailbox and need to be re-enrolled. e.g. When we deploy via Sophos the device EAS server settings are smc.domain.com but then mostly on weekends change to eas.domain.com and need to be re-enrolled.
This doesn't happen with iOS devices.
Does it show any specific error? Please take a look at this KB article and see if it helps.
No errors. Interesting article but it doesn't appear to be the issue as there are no "failed to resolve active sync" errors in the easproxy.log.
No errors when this occurs. All we can see is that on the Samsung device the server address for the Active Sync server changes to a different address. This address isn't available from outside the domain for Active Sync, hence email then fails to sync.
Is it something as mentioned in this article?