x264 mkv audio issues and x265 mkv that freeze the box

Hi everybody,

I have this mediabox from some months, all was great until some days ago...

All started with some 1080p x264 mkv with audio issues... every few seconds audio stopped. With other mediaplayer (popcornhour a300) and with Samsung smart tv dlna player all is ok, no audio problem...
Very strange...

And now, I tried some 720p x265 mkv, kodi can not start them... Some times they start then immediately come back to kodi, and all system freeze, I have to turn off leaving power plug......

x264 mkv audio issues and x265 mkv that freeze the box