We had the same issue. Are you also using WPS Hide Login plugin? We deactivated that, and the sitemap/404 issue disappeared.
I have the same problem, sitemaps are showing 404 errors. On our sites we also use WPS hide login plugin. Deactivating that plugin has fixed the 404 issue for sitemap pages for us. Not ideal long term, but a short term fix.
@edo888
Thanks for your reply. In the end, we removed that plug-in and installed gtranslate instead, and that is working well.
Thanks again.
