playback pause and hangups problem with external HDD and z9s

[nikeairmax]

Hi guys,

I own a Z9S player with the latest firmware installed. When watching full 1:1 Blu-Ray rips the movie pauses for 1-3 seconds during a movie quite some times. Also, some movies will completely keep hanging; this happens sometimes after 5 minutes and sometimes also only after one hour or so.
It happens with both .m2ts, .ISO and BDMV folder structure rips.
I m using a external HDD. I have tried 2 external HDD's and both have the same issue (WD MyBook 3tb formatted FAT32 and a WD Elements formatted exFAT).

Tried it with the native player, with home theater and with the ZDMC player: all the same issue.....

What could the problem be?

Thanks

[futeko.com]

Are the external HDDs independently powered? If it happens on all players then it would suggest that the problem is on the USB / HDD side. I'm thinking maybe the USB port is providing only marginal required power to the HDDs.