Fast- Forward/-Rewind do not work sufficiently

[HDMediaplayer]

HIMEDIA H8 OCTA. 7-JAN-2016. FIRMWARE HMD-1.0.9 FUTEKO-EN (12-JAN-2016 RELEASE)

Configuration:
I use LAN and NFS-share with a Gigabit switch and a powerful Synology NAS.
I use a Full-HD Panasonic Plasma, no 4K TV.
H8 is connected via a modern Pioneer AV receiver to the Plasma by HDMI.
I made all tests with Kodi.
5.1 speaker configuration and pass-through is enabled for all supported audio formats in Kodi.

Kodi settings:
libstagefright: DISABLED
MediaCodec: DISABLED
rockchipcodec: ENABLED
rockchipcodec23976: ENABLED

Error:
Tested with Full-HD movies.
Fast- Forward and Fast- Rewind do not work sufficiently.
2x and 4x Fast-Forward works (with 3D-ISO only 2x work).
Fast- Rewind and all other Forward speeds do not work; the movie freeze after some seconds.