I too have had UMC problems. I think I'm on my third or fourth now. It started acting flaky a couple of weeks ago again. I would plug it in and get no action at all (ring would just stay white) or it would clunk white-blue-green-red a few times. I could get it to work by playing around a bit. This is my typical failure scenario. The UMC car connector "looked" clean (it normally just hangs in my garage), but I thought I would try swabbing it out with a Q-tip. Well even though it looked clean, the Q-tip came out very black. I worked it a bit more with the Q-tip and now it is working much more reliably. I can only get in to the two big openings, not the smaller ones, and I was as gentle as I could be. I'm going to mention this at my next Service visit, and would like to know if there is some recommended contact cleaner that I could spray in there from time to time. I don't want to just go willy-nilly with WD-40 or similar until I get the go-ahead from Tesla, but think this might be the cure. To pull it back to this thread, my concern with the Clipper Creek unit is that, over time, the J1772 adapter may suffer the same fate of getting "dirty" and unreliable. Right now, my J1772 adapter works fine, but I only use it maybe once or twice a week compared to every day with the UMC.