>>/4591/
Not for me no, IIRC that means the tok is in the wrong LUMA key.
If it works fine after conversion? Ignore it.
If it doesn't work fine? Do this:
ffmpeg -i input.mp4 -bsf:v "hevc_metadata=video_full_range_flag=1" -c:a copy -c:v copy output.mp4
And then just run the conversion on the output.
There's also an option that it's not the LUMA key thing but old ffmpeg not handling something that's new in the standard, in which case you will have to update it.