Symptoms
If a calendar invitation that includes Korean text in the message body is sent to a user whose display name includes Chinese characters, the body text arrives garbled in the receiver's calendar in Microsoft Exchange Server 2019 or Microsoft Exchange Server 2016.
Resolution
To fix this issue, install the following cumulative update, as appropriate:
Cumulative Update 10 for Exchange Server 2019 or a later cumulative update for Exchange Server 2019
Cumulative Update 21 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.