Gallery stops loading images until I scroll down

I’ve been searching through this help page until I found this thread (LINK) but I am quite sure that I am accessing my NC using a standard HTTPS connection, not WebDAV (how can I confirm?)

The observed behavior is that only a small portion of the images are loaded and no more are loaded until I scroll down.

While I can accept some low performance given my RPi3 setup, at least let all the images load while I spend some time looking at the first pictures, don’t you think?

Am I missing something here?