I tested it with an Android project, never tested with iOS.

The current version of the plugin uploads the mapping.txt file but in the AppCenter console it appears as "upload-<TIMESTAMP>.zip". It seems AppCenter cannot use the information from this file to deobfuscate crash reports.

To make the uploaded symbol files (here mapping.txt) working in the AppCenter console the Android VersionName and VersionCode must be uploaded, too.

When i upload a mapping.txt manually to the Webconsole or using the CLI everything works.

Btw. when using the CLI, which i now use as a workaround, versionName and versionCode are mandatory parameters.