Message doesn't mark as received and appears with each request.

[abezruchenkov]

Hello, we've been using signal-cli for a long period of time (with signal-cli-rest-api wrapper) and everything worked fine.
Today we've encountered some really strange behaviour with one message. It appears with each receive and seems like it doesn't mark it as read at all.
Our system collects new messages each minute and we have collected several hundreds of these messages with the same timestamp.
What's strange about this messages - it has NULL message text, it has no attachments and in groupInfo section we see
"type": "UPDATE"

Could anyone help or point the right direction?
Thanks!

[AsamK]

Maybe the verbose log prints something useful -vv