alexa voice command for video: fastforward and rewind not supported? /

I contain an video app for the FireTV and voice commands for play,pause, skipNext, or skipPrev work fine,but when calling fastforward and rewind Alexa says it's "not supported".

I'm using MediaSessionCompat and MediaSessionCompat.
Callback. In the Callback I contain overridden onSeekTo, onRewind, or onFastForward but it still says it's not supported.

Also contain the Alexa voice command permission in manifest
My only hunch is that I might need to use the Video Skill API for that functionality.
Any insights Appreciated!

Source: amazon.com