Nextcloud version: 20.0.10
Operating system and version: Ubuntu Server 20.04 ARM64
nginx version: nginx/1.18.0
PHP version: 7.4.3
MariaDB version: 10.5.9
I am running Nextcloud 20.0.10 on Raspberry Pi (Ubuntu Server 64-bit). Nextcloud 21 has been released long time ago, but it still doesn’t show update available. I’m using “stable” channel. How can I check why the update isn’t available for me?
You can change to “beta” channel. Then you can see the update. Hafter update you can change back to “stable”.
Or do you use a special Pi version?
Sorry i do not use NextcloudPi.
I use regular Nextcloud installation, not NextcloudPi or Docker.
After switching to beta channel it shows the update to version 21. I was pretty sure that Nextcloud 21 is already stable, but in that case I will wait for it.
Nextcloud 21 is Stable.
Now I’m confused 
So why is it available only in “beta” channel instead of “stable”?
Nextcloud does staged rollouts for new releases…
https://nextcloud.com/release-channels/
### Where is my new stable release?
Nextcloud makes new versions incrementally available to user installations in the Stable channel. When a major new version comes out, we wait about one week and only when no problems are found we start the roll out in steps of about 20% of our user base per week. If you maintain several servers, this means some get it sooner than others. Sometimes, an issue is found that was not caught during our pre-release testing, so we delay the roll-out until the fix is available. As a result new release is typically only available in the stable channel after the first minor release. Sometimes it can take even a bit longer. Users can always upgrade sooner by choosing the beta channel, which typically tracks stable releases immediately after publishing.
Is that happening especially if you are using LDAP? Because on the installation without LDAP the update message came after the first or second minor relase, however all LDAP connected instances still don’t get any messages yet.
So are there some LDAP related issues?
None that I am aware of. But I don’t use LDAP myself, so I’m not a 100% reliable source 
Of course, you can always update manually or use the “trick” with the “beta channel”. Either way, I would recommended to run a test instance and test major upgardes first. Especially if you use your cloud in a company and your users have to work with it productively. Because even if the update is offered to you, you can’t always be a 100% sure that everything will work without any problems.
ah ok, often in such cases there are still specific issues. Btw I’ll do that the other way around, I create a snapshot of the container, update and if it blows, just revert it, and everything is back to normal. So I do not need an extra staging env for that.