Symptoms
In Microsoft Exchange Server 2019 and Exchange Server 2016, when you open Microsoft Outlook in an online mode profile and drag a message from the Inbox to the Calendar folder or a task folder, you may notice that the Calendar or task object displays an unexpected " " string in the empty line between the lines of the message text. For example,
Hello User001,
 
This is a test…
This issue also occurs in the Outlook on the web client (previously known as OWA).
Resolution
To fix this issue, install one of the following updates:
For Exchange Server 2019, install the Cumulative Update 8 for Exchange Server 2019 or a later cumulative update for Exchange Server 2019.
For Exchange Server 2016, install the Cumulative Update 19 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.
