issue with rewind=1 and persist-last in some situations

Incident Report for Ably

Resolved

Between about 14:00 UTC on the 20th and 17:00 on the 21st, on channels with the persist last message (https://ably.com/docs/channels#rules) channel rule enabled, attachments with `rewind=1` in situations where the most recent message was published over two minutes ago but still somewhat recently (and where the channel has been continuously active in a given region since the message was published) may not have had that rewound message correctly delivered to the attaching client. We apologise to anyone whose application was affected by this.

Posted Oct 20, 2026 - 13:00 UTC