Thank you for your reply!

There’s no galleries per page option in settings > general (for both the plugin and wordpress). It might be due to the poor Dutch translation.

However, there is an option called Galleries per album. It is set to 9.

Above that option is another one called Album template. If i choose the default one or my custom one, it doesn’t make any difference (even with the default twenty xx theme).

I’ve disabled all other plugins besides image-store and tinymce.

All gallery’s are public (so no password). Yet only one shows up. If i add another public gallery, the new one shows. Still only 1 gallery is showing.