Hi,
according to a newsletter I got about 2 weeks ago, NC15 has been released. However my Nextcloud setup tells me, NC 14.0.4 is the latest version in the stable channel.
When will NC 15 be available for update through the stable channel?
New releases are normally pushed to the stable channel after the first or second minor upgrade (so probably some time in January). If you want to upgrade earlier, you can switch to the beta channel, upgrade to NC15, and then switch back to the stable channel. Don’t forget to backup.