Some unicode letters are not correctly displayed - For example setting the following motd in server.properties:
motd=\u00A74\u2764 \u00A7d\u00A7lV\u00E4lkommen \u00A74\u2764
The two hearts (\u2764) will be garbage, but the 'ä' (\u00E4) will be correct.
Works fine in 1.13.2, but not in 1.14.
Are you using any resource packs?