Looks like a recent update is forcing all edits for SPPB modules through the frontend via an "Edit with SP pagebuilder" button which might be good for ease of editing, however the routing doesn't seem to work properly with sh404SEF installed.
When I click on that button to edit the module I get a Page Not Found error, the same as when we try to edit or preview a page from the backend with sh404SEF enabled.
Since it looks like we are being pushed to edit through the frontend this therefore means any SPPB modules are now uneditable?