mp4 can FF and RW but mkv not

Lately I been experiencing problems with remuxed mkv files that wont fast forward or rewind (no trick mode supported). This happened in rare times with old mp4 files, but the new ones exhibit this problem almost all the time.

The strange part is: When the mp4 file is played through dlna I can do FF or REW.
But, when remuxed to include subtitles it displays the “not trick mode supported” error message and stops playing.

I´ve been looking into various settings in mkvtoolnix but I still can´t get how to passtrough the mp4 through the mkv remuxing in a way to preserve the FF, REW feature.

Any help or suggestions are welcome!

have you tried a different muxer to see if that’s the problem ?

eg. My MP4Box (designed primarily for muxing / demuxing mp4’s)