Symptoms
In Microsoft Exchange Server 2019 or Exchange Server 2016, when you create a search folder under the Top of Information Store in a custom client application, the default retention policy is applied to the items in the search folder, even though those items should be getting the policy from the folder where they actually reside.
Resolution
To fix this issue, install one of the following updates:
For Exchange Server 2019, install the Cumulative Update 5 for Exchange Server 2019 or a later cumulative update for Exchange Server 2019.For Exchange Server 2016, install the Cumulative Update 16 for Exchange Server 2016 or a later cumulative update for Exchange Server 2016.
References
Learn about the terminology that Microsoft uses to describe software updates.