Hi guys, I am just wandering if I am missing some steps to configure the guide in Ekos…

My Kstars/Ekos installation is on Mac OS 10.14.6 and I use a ZWO ASI 1600 imaging camera and ASI 120 MC-S as guiding camera. 
The guiding camera is powered via the imaging camera through an USB cable. The mount is directly connected to my Mac via EqMod cable opportunely configured in Ekos. Just to be sure that everything is ok I attach a screenshot showing the configuration of my devices in Ekos with the opportune drivers. 
I had several problems in the guide. The problem I experienced are the following:

1 - During the guiding process, the modality of acquisition of the guide camera automatically switches from 16 bit to 8 bit. I obtain the following message that report this problem:

2020-10-16T20:57:30: [INFO] Switching to 8-bit video.

2 - I am not able to guide precisely. I initially obtain a drift plot that is almost stable (residuals around 1.5 arcsec) for few minutes. After some minutes, however, the plot starts to be highly unstable with drifts of also 10 arcsec. Unfortunately I have not an image to show you for this case…

I checked several times the balance of my equipment, then I would exclude this kind of problems.

Just a little note (I don’t know if this could contribute in part to these problems)…
All my USB outputs cables (that of the imaging camera, Eqmod, focuser.. ) are connected to an USB 3.0 HUB, that is powered directly from my external battery and connected to my Mac with an USB 3.0 cable. 

How can I solve these problems? 
I thank you very much for your suggestion and comments.