Cannot figure out how to perform docker update

Synology NAS
Linuxservers docker image: latest
Original install: 23.0.0
Trying to update - (also tried downgrade)

done:
export docker settings
delete container
delete image
download new docker image
import settings
NC runs and connects, but version remains at 23.0, regardless of using a 23.0.2 or 22.2 or whatever image.

I assume this is because there is a data file that is not changed.
I cannot figure out how to do the docker update correctly - none of the tutorials on the web cover my problem.

Can someone guide me?

please never do this it’s not supported and may damage your instance

at the moment :latest tag points to ENV NEXTCLOUD_VERSION=23.0.2 this what you are expected to get if you pull the image now.

see Upgrade instruction on Docker Hub https://hub.docker.com/_/nextcloud?tab=description

Update to a newer version

Updating the Nextcloud container is done by pulling the new image, throwing away the old container and starting the new one.

It is only possible to upgrade one major version at a time. For example, if you want to upgrade from version 14 to 16, you will have to upgrade from version 14 to 15, then from 15 to 16.

Since all data is stored in volumes, nothing gets lost. The startup script will check for the version in your volume and the installed docker version. If it finds a mismatch, it automatically starts the upgrade process. Don’t forget to add all the volumes to your new container, so it works as expected.

$ docker pull nextcloud
$ docker stop <your_nextcloud_container>
$ docker rm <your_nextcloud_container>
$ docker run <OPTIONS> -d nextcloud

Be ware that you have to run the same command with the options that you used to initially start your Nextcloud. That includes volumes, port mapping.

When using docker-compose your compose file takes care of your configuration, so you just have to run:

$ docker-compose pull
$ docker-compose up -d

thanks - I was confused by what could be done in the Synology Docker GUI and what had to be command line. What I ended up doing was:
From the Docker GUI in Synology:
Select container, then Settings → export
Store to a local place (e.g. /docker)
Then command line:

ssh admin@10.1.1.3
sudo docker stop linuxserver-nextcloud
sudo docker pull linuxserver/nextcloud
sudo docker rm linuxserver-nextcloud

then back to Docker GUI
Containers, Settings → Import