This probably is something wrong with the settings or the process I am following but here's the case...
I have tested this with various footage (709, log, dpx, mxf... etc.) and 24/25 ACES, YUV all the possible combinations and on 3 different stations... all using resolve 10.00lite.073
I am getting bizarre results trying to use a LuT that I have created on Resolve using a grade.
When I apply the 3D LuT the image looks as it's been solarised and when I looked into the .cube file as a text I see a lot of 0.000000 values quite high on Red and Blue channels, which agrees with what I am seeing.
This is the same if I use the LuT on the node or in the Preferences.