No sourcemap in Sentry

I followed the readme closely (but had to make changes to make it work in the current NS setup), but I can't get sourcemaps to show up in Sentry. I'm 100% certain the source maps are uploaded (I validated in Sentry), and I'm also 100% sure that the release and dist in the Webpack sentryWebpackPlugin match up with what I configure in the plugin.

But it still ends up like this in Sentry:

Any idea what I can do here? I also tried with and without rewriting. My webpack looks like this now:

    if (env.uploadSourceMap) {
        webpack.chainWebpack((config) => {
            config.devtool = false;

            // Write away sourcemaps outside build dir.
            const customSourceMapDevToolPluginInstance = new SourceMapDevToolPlugin({
                append: `\n//# sourceMappingURL=[name].js.map`,
                filename: '../../../../../../sourceMap/[name].js.map'
            });
            config.plugin('SourceMapDevToolPlugin').use(customSourceMapDevToolPluginInstance);

            const customSentryWebpackPluginInstance = sentryWebpackPlugin({
                rewrite: true,
                release: {
                    name: `${appID}@${appVersion}+${buildNumber}`,
                    dist: `${buildNumber}.${platform}`,
                    setCommits: {
                        auto: true
                    }
                },
                ignoreFile: '.sentrycliignore',
                include: [join(__dirname, `platforms/sourceMap`)],
                telemetry: false
            });

            config.plugin('sentryWebpackPlugin').use(customSentryWebpackPluginInstance);
        });
    }

Start with the README and the shown Webpack configuration, especially SourceMapDevToolPlugin, the generated sourceMap directory, and sentryWebpackPlugin's release, dist, include, and rewrite settings. Verify that the uploaded artifacts match the event's release, dist, and source paths; done means Sentry renders the original source locations instead of the bundled stack.