Pi-hole 5.17 in docker image?

Hello,
I am pulling latest tag on the pi-hole docker image and can't seem to get the latest version of pi-hole's source. The dashboard after a synology docker gui "reset" that should pull the latest version of the container still says "Docker Tag 2023.03.1 · Update available! Pi-hole v5.16.2 FTL v5.22 Web Interface v5.19."

I'll try to follow the instructions on

Maybe someone else is having a similar issue on synology and docker?

I was able to solve this by going into the registry on the docker Synology GUI, clicking download for the pihole/pihole, and then choosing latest. Even though I already have the tag latest in my "images" tab, manually downloading gave me the newest version.
After downloading the latest image, stopping the running pi-hole container, clicking "reset" in the "Action" drop-down utilized the new image. Then, of course, I started the container again and have the expected latest version running.
I believe the Synology docker GUI, the respective docker-cli commands issues by the GUI, and latest tag manual down could be incorrectly implemented. I don't think having to redownload latest every time is the intended behavior, but that's for a different forum. Haha.

I'm not familiar with Synology's management layer for Docker, but your description almost reads as a similar observation for Portainer from about 2 years ago, where Portainer kept the container's previous environment (including version information) even when the container was recreated.
See Pihole Portainer/Docker 5.8.1 startup error? - #9 by ptruman.

Drawing an analogy from there, perhaps Synology has indeed pulled the latest image, but still shows the environment from the last run?

No worries. Figured out a work around and got things flowing again.
I've looked into portainer, but if I'm going to have to learn an orchestration it'll be k8 kubernetes and learn some more docker compose stuff.