LMS 8.2.0 on Docker: update available notification?

I'm running LMS v8.2.0 from the LMScommunity Docker image on a Synology DS1511+ (which all works very well, thanks!)

I'm somewhat confused though about the "new version available" notifications that LMS gives (green up arrow in Material Skin).

I was on 8.2.0 - 1617991288 previously. Yesterday I changed the docker image to 8.2.0 - 1619728313 because of the 'new version available' notification.
But I still get the notification, now I'm wondering what is going on? (Most probably it is my lack of understandig how Docker works :o )
I suppose pushing a newer docker image will trigger the notification, even if it is the same 8.2.0 version number?

Thanks, Bart