Directory Services 16 - PATCH call removes user from groups

When running the following REST call to the user patch operation the user is removed from all groups it is a member of.
Example:
The user is a member of:

REST Call example

After a successful call the result is the email is update, however the user is deleted from all its groups:

This seems to be a pretty serious bug. Is there a fix or temp workaround for this?

Thanks in advance!