Self-hosted docker beta not the most recent beta?


I am using the docker image of Bitwarden self-host:beta from docker hub. For about 45 days now, I am on Version 2023.8.2, but I just realized that there are newer beta versions of Bitwarden on docker hub.

The image I chose for my container was bitwarden/self-host:beta and I thought that would leave me with the most recent beta. But it doesn’t and my Synology NAS won’t offer me updates for Bitwarden in contrast to other containers and images I am using.

Is that normal behavior for Bitwarden that the beta tag gives me an older beta version and I have to select newer versions explicitly?
For example bitwarden/self-host:2023.9.3-beta