It’s no longer possible to send secured messages to Citi. It’s not clear why Citi has removed this functionality, although it appears at least some things will be done via live chat instead of secured message. If you have existing secured messages it’s still possible to view those, but there is no longer a ‘reply’ option. I would back up any important secured messages you have, especially if those messages contain any promises (e.g ‘yes we will match you to that bonus or yes you’re eligible for that bonus’).
Hopefully they are just replacing secured message functionality with live chat and it will be possible to ask for matches via live chat (update: has been possible previously). I know a lot of readers prefer to just ask for these types of matches by text rather than having to call in.
Hat tip to bplturner