I'm not an expert in LOG, but I would like to mention that with my G7 cams ETTR+CineD works fine for me in my studio, but I get weird and even unusable results under bright spotlights (like theatre or concert lighting). I've had blown highlights with weird colors even with zero zebras on screen. And using multiple cams I get the same weird results sometimes. So it could be that there is a condition in which ETTR is fooled by the camera somehow, depending on both the lights and the subject material. However, in the studio under controlled lighting I get a bit more DR with ETTR (tested with Leeming LUT and my own LUTS).
At least you were smart enough to reset it, I just happily filmed away........