[Plugin: NextGEN Gallery] Latest and random widget: lightbox keeps jumping

Hi all!

finally started to use NextGen a bit more on my site, but ran into an annoying behavior. I use the “latest pictures” and “random pictures” widgets in the footer resp. in the sidebar (btw the prob is the same if there is only one of them).

You click a thumb, lightbox opens up, perfect. You click “next” – and the screen jumps up to the header section of the page (if you were somewhere down the page), and the next image is displayed about 1/3 lower, and so forth. Only the first image is displayed correctly. (if my description does not make sense – check it out on https://www.elfenwald.org/blog , click a thumb in the sidebar, and then try to view the other images one by one – have to scroll down every time…)

Is this a bug, or incompatibility with some css/plugin/whatever, and has anyone any idea how to fix it?
I found similar topics on the forum regarding galleries, not the widgets, and none of them seemed to contain a solution.

Thanks for any hints!
Martin

https://www.ads-software.com/extend/plugins/nextgen-gallery/