Try using a spawn stream profile instead of pass or htsp. For the “Command line” argument in the stream profile settings you could try:
/usr/bin/ffmpeg -hide_banner -loglevel error -i pipe:0 -vcodec copy -acodec copy -f mpegts -tune zerolatency pipe:1
Mime type: video/mp2t
Keep the mux URL the same as it was originally.
Let me know if this works.
