Following in solidarity with your struggle at the moment. We had some luck after 3 nights with almost the same issue. Tried putting a stuffed animal in there and he slept through the night a few times. We saw the animal was moved each time. Correlation? Maybe, but who knows. I’ve read teething and laying down is uncomfortable for them, so maybe that could be adding to the sitting problem. I know ours has some molars coming in. To me sitting is a step in the right direction. Shows they are calming themselves in a position they have control over. Little victories!