axios's onUploadProgress uses XMLHttpRequest under the hood in React Native, but there's a known issue where axios's FormData handling on React Native Android can fail (it sets the wrong Content-Type header, breaking multipart uploads). That's why the I used raw fetch instead before. Now, I kept XMLHttpRequest directly because it gives us both: reliable FormData uploads on Android AND progress events — which fetch doesn't support. It's essentially what axios would do internally, just without the Android FormData bug.

Is this issue fixed in axios or not?