In Chrome's inspector I see
DevTools failed to load SourceMap: Could not load content for https://devsite/++plone++production/++unique++2020-05-13T09:54:10.825507/plone-compiled.min.js.map: HTTP error: status code 404, net::ERR_HTTP_RESPONSE_CODE_FAILURE
but rebuilding bundles, toggling develop mode, deleting things in
portal_resources/resource_overrides did not generate the missing map file.
Where should I expect a generated map file to be served from by Plone?