Drobo 5D - Never Works Properly Since Purchase

I have had nothing but trouble with the Drobo 5D. Even when I keep everything up do date it still has issues. I am using it with a older iMac (2010) and it unmounts practically every day and some times a few times a day. I am using the USB because my mac doesn’t support thunderbolt at the time. I read that a lot of people said the same thing, that it down’t work well with the usb for a lot of imac’s. If it down’t, why don’t they fix it? What else can you do if you can’t use the USB and you can’t use the thunderbolt? I would really like to fix this problem so my Drobo functions properly. Can anyone help with this?