Judging by your video, there’s probably nothing wrong with your Space – it is sitting at about 49.5, and circuit noise is making it flicker between 49 and 50 – this is mainly a display effect and can probably be ignored. You may find it distracting, however.
If you move the knob to other positions, does it still happen ? If it happens on all values, it may be a dirty pot or a fault in the circuit that reads the pot. I don’t think it is the ribbon, but if you can fix it, well and good.
It does it regardless of where the pot is. I sprayed some contact cleaner in the pot and that did not fix it. HOWEVER, I noticed in the sheilding tape (on the top PCB) there was an indentation from one of the legs of the “low” encoder. It was not punctured through, but there was definately enough pressure to put a bump in the shielding piece. I cut a 1/2″ x 1/2″ piece of electrical tape and put it over the soldered legs. I’ll have to see if that fixed it this evening.