If by “still alive” you mean that they still work if you paste them into a browser, than yes that’s correct- and there is no problem with that. It’s the way Webflow works.
If you mean they’re still being promoted for SEO, I’m not sure where that would be happening. Webflow’s paginated URLs do not appear in the sitemap.xml, and with FS Load more, those next & prev buttons are likely removed from the page as well. Googlebot typically indexes after running scripts, which means those pagination querystrings should no longer exist.
Other engines like Bing may behave differently.
While you could probably do that using Webflow’s wildcards, it would break FS Load more.
FS Load more works by “clicking” those links and walking through those pages to retrieve the contents. If you redirect those links, it will just keep getting page 1 and nothing else.
I really think that you’re spinning your wheels here on a non-problem, and you’re more likely to cause harm than benefit by trying to change how Webflow works…
However, if you’re OK with the risk of de-indexing the page altogether, you might be able to achieve what you want with a script-generated META noindex tag that you only insert on paginated pages.
On page 1, where there is no querystring, your page head would contain;
<meta name="robots" content="index">
Whereas on pages 2 … n, when the querystring exists, you’d generate;
<meta name="robots" content="noindex">
This may or may not work, depending on the search engine, how it handles querystrings and how it handles scripts.
However make sure you do not use this hack with a canonical URL. Webflow’s canonical URLs already declare that there is only one page of significance here- the one without the querystring, so from Google’s perspective if you have a
noindex META and that canonical on the same page, you’re telling it not to index page 1.