22.1.0 RC1 (beta) vs. 22.1.0 (stable?)

perhaps someone can explain the upgrade process.

I was on Nextcloud 21 (Stable)
On release on Jul, 6. 2021 i went to Beta and got Nextcloud 22
After that i went back to Stable.

On Aug, 5. 2021 there was an offical upgrade to 22.1.0 (blog)
It is ok that not all servers (Stable) get the update at the first days.

Today i went to Beta.
I got 22.1.0 RC1 on Beta.
Why? I do not understand it.
Or is 22.1.0 RC1 newer than 22.1.0 ?

Can someone explain it?