Drobo unmounts constantly; starting up again requires strange cable combinations

Hello, my Drobo 5D is connected via USB 3.0 / USB-C to the newest Mac Mini. For the last several months it periodically unmounts itself, but now it does it after only being mounted for a few minutes.

To get it to start up again, I have to unplug the USB 3.0 cable, unplug the power cable, plug the power cable back in, hold down the power switch, then once it goes through its startup routine, I can plug the USB 3.0 cable in, my Mac Mini mounts it, and all is well for a few minutes before it unmounts itself again.

I’ve removed all of the drives and then got it going, Drobo Dashboard sees it, it has the one red drive light for “no hard drives,” and then it shuts itself off again after a few minutes.

I’ve had these unmount issues periodically with multiple Drobo products, but this is a show-stopper. Any help is very much appreciated. Thanks.

Did you ever figure this out? I am having the same issue…Drobo 5D on a new Mac Mini (OSX 10.14.6). It is insanely frustrating and now I can’t trust that data is being backed up appropriately.

As it stands, it stays mounted until I reboot. At that point, I have to wait for Mac OS to restart, then remove the USB cable and plug it back in again, then allow the Drobo to mount. It doesn’t mount on its own at restart. Not ideal, but livable.