This is not expected behavior. We tested with forced subtitle tracks and were able to retain them normally.
It’s possible that:
The forced subtitles were not properly flagged in the source file
Or the subtitle track was not selected during processing
We recommend you:
Check if the subtitle track is marked as “forced” in your source (you can verify with tools like MediaInfo)
Make sure the subtitle track is selected in UniFab before processing
Try remuxing the original file to ensure all tracks are correctly recognized
If the issue still occurs, please provide your source file info or a sample so we can further investigate.