I use Nextcloud to share folders with images. Unfortunately, since upgrade to Nextcloud 18, it is not possible to view images in fullscreen. Images are now downloaded on click, in previous version it was possible view them in a lightbox-like fullscreen view.
Is it possible to enable lightbox for shared links in Nextcloud 18?
As I understand it (still being on NC17 myself) the issue is that the Gallery app was replaced with a half-baked less developed and feature-rich Photos app. The software that handles the process you’re describing was changed in NC18.
I have a test setup that is running NC18, but I haven’t really messed with photos on it. I guess I should take a closer look because I want to upgrade for the integrated ONLYOFFICE. It seems better than Collabora, and I could never seem to get the Regular ONLYOFFICE doc server to work.