We discovered few users having mailboxes on both ONprem (2010) and Online. Get-mailbox, get-recipient, stats work on both the onprem & online. get-recipient shows user mailbox even the EMC search shows user mailbox.
MSOLuser gives account inf and licenses assigned.
From get-mailboxstat -include move history we have logs that these mailboxes are moved to online. The onprem mailbox stat shows very few or no emails.
Users are having issues with autodiscover. Please advise with the resolution steps for this use case.