I’ve been encountering this on my Nomad 883 Pro (used/2nd hand). Weird, I searched, but didn’t find your post, so ended up posting ( Job hangs, but spindle stays on )
Regarding the Capacitor soldering mod, does anyone have a schematic and a location of where it should be added? The hangs/disconnects are annoying while setting up… but costs milling stock when it happens mid-job. 
Looks like I might be taking a look and re-checking wiring/boards in the near future on my Nomad.