When you say that you turned on OpenGL - do you mean you enabled the driver using raspi-config?
EDIT: I donāt know if this will help your situation, but I eventually gave up on using GC on the pi. (And on my laptop, for that matter. ) The instructions to install the Webcontrol docker to a standard Raspbian install are fairly complete, and it was the way that I finally got my unit working.
webcontrol is a browser based version of ground control, there is a premade pi
image that manages webcontrol as a docker image (a very nicely done packaging
mechanism)
My experience with Octoprint for CNC was it was laggy and unpredictable. These are not good qualities when a heave weight is swinging around with spinning blade.