When you click on the archives in the right sidebar, which were added using the widget, no archive file link takes you to the actual archive and they default to the home page. It does the same whether the widet is set to dropdown or post counts.
I’ve just changed some settings on the Yoast SEO plugin which was seemingly corrupting things so I have most archive months now working instead of the first month of this April – ?? Caching issue or something else?