Floating gallery - two element click selectors

What I want:
I want to scrape the download links from every page in a (floating) gallery.

The problem:
After clicking the text/thumb "Bekijk register (View register)" a (floating) gallery opens. There is no direct link to the gallery. I have to click "Bekijk register" first before being able to view the gallery. Whenever I hit refresh (F5) or copy/paste the url the gallery disappears.

What I tried so far:
I used two Element Click Selectors (ECS). First to open the gallery by clicking the "Bekijk register". Second for pagination and selecting the download links. The first ECS works fine. However after that nothing happens. I guess somehow the second ECS doesn't start where the first left off but starts again from the start url.

Url: https://salha.nl/bronnen/genealogy/bladeren-door-genealogische-bronnen/registers/cad3fd8c-b2d0-f9ae-761c-2496df45e365

Sitemap:
{"_id":"salha","startUrl":["https://salha.nl/bronnen/genealogy/bladeren-door-genealogische-bronnen/registers/cad3fd8c-b2d0-f9ae-761c-2496df45e365"],"selectors":[{"id":"open","type":"SelectorElementClick","parentSelectors":["_root"],"selector":"span span","multiple":false,"delay":"500","clickElementSelector":"a.image","clickType":"clickOnce","discardInitialElements":"discard","clickElementUniquenessType":"uniqueText"},{"id":"scan-pag","type":"SelectorElementClick","parentSelectors":["open"],"selector":"a.download-button","multiple":false,"delay":"500","clickElementSelector":"a.next-button","clickType":"clickMore","discardInitialElements":"do-not-discard","clickElementUniquenessType":"uniqueText"}]}

Thank you!