In a SQL Server Always On environment, you start a large transaction on the primary replica. If a new page is allocated by a page split in the transaction, a PAGE IX lock migrates to this new page on the secondary replica. In this situation, a conflict with a PAGE X lock occurs, and a deadlock condition causes a deferred transaction in the secondary replica.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
Learn about the terminology that Microsoft uses to describe software updates.