I had this same issue on Android 13/14, high-bitrate live streams (2K/60fps ~25 Mbps) played fine on some devices but stuttered on others. For me the cause was the same: device-specific decoder limits and no adaptive bitrate. What finally fixed it was routing the stream through FastPix instead of sending it directly to clients.

1. Push the stream to FastPix (RTMPS/SRT).
FastPix ingests high-bitrate streams reliably and removes device-to-device decoding differences.
https://docs.fastpix.io/docs/how-to-livestream

2. Let FastPix handle transcoding + ABR.
FastPix automatically creates adaptive renditions (1080p/720p/480p), so newer Android devices can switch to a bitrate they can handle instead of choking on the full 25 Mbps.
https://docs.fastpix.io/docs/live-stream-overview

3. Use the FastPix HLS playback URL.
I replaced my direct playback with the FastPix HLS URL and the stream became smooth on every Android version, no jitter, no green frames, no decoding glitches.

4. Use analytics to confirm bottlenecks.
FastPix’s stream analytics helped me verify whether the issue was network, decoder, or buffer behavior.

So yes, reducing bitrate on the client helps a bit, but the real fix for me was offloading the entire encode > transcode > ABR > playback pipeline to FastPix. It completely solved the latency/stuttering issues.