Please help me with my ground wiring for my sherline lathe - running into issues

Hey everyone, I am having an issue where isolated analog output is failing to control my sherline spindle. This issue started after I added a spindle encoder. However, there are other issues going on that make me think there is a serious issue in my ground circuitry. I did a crappy job and there are probably lots of ground loops. Despite removing the encoder, I still get spindle control issues. As it stands, both axis work fine. At one point prior to encoder, everything worked fine.

What makes me suspect a (Dangerous) ground issue - is that moving around my isolated DC power brick (Which hooks into spin- and spin+ to get me my 0-10v range) can sometimes cause the spindle to turn on.

Currently, both axis work fine.

Therefore, I am planning on redoing my wiring, particularly when it comes to ground circuitry. I made a diagram of the new proposed ground circuit and wanted to see if anyone could verify this should work correctly.

My biggest question for this is: Does step- and dir- connect to GND on the steppergen of my 7i96s, or to the ground bar that connects to the sherline frame?