After a bit of research, it looks like it’s a conflict with sh404sef.
I found a workaround, but it’s only fixing things that are already done.
– Put site offline
– I downloaded Purity 3 Template (or any other template not using infinity scroll)
– I deleted all the URL from the Category in trouble. So I deleted Category/, Category/Page-2.html, Category/Page-3.html etc.. (there was 304 pages…….)
– After all URL are deleted, I switched to Purity template and when to the Category that was in trouble.
– Automatically, all URL for the first 10 pages are done.. I scrolled to all pages (zzz) until I reach the end)
– Switch back to JA Magz, now infinity scroll is working!
So it does work for now and I don’t think anyone will go until the end for this section, but the problem is some section are only 2-3 pages old and will grow. Is there a solution for those or I will have to do the same procedure?
Thanks