OSMC is flapping on RPi3

http://paste.osmc.io/xopitalahe

movie is played in a flattered manner but also menus are not moving fluently.

any ideas please ?

update:
it disappears when i disconnect the external disk connected to the RPi via USB.
i ran fsck on the disk and it came back clean. three partitions of ext4.
i use this disk in this configuration for a long time with no issues.

thanks.

13:55:41 404623.562500 T:1956365232 NOTICE: DVDPlayer: Opening: /media/GideoniStorage/Movies/Whiplash.2014.BluRay.1080p.5.1.x265.HEVC-Qman[UTR]Rnd.3.mkv

Is a 1080p HEVC file which won’t have hardware acceleration, so I wouldn’t expect that to play well with these builds.
Stick with H.264 video files.

thank you for your replay.
this happens with movies that streamed before fluently.

here is a debug logs with fresh reboot and performing minimum of operations to recreate the problem:

http://paste.osmc.io/vacowomuxi