I had the same issue on both. Spinning it didn't do anything even with the bleeder open for me as well. I had to use excessive force with the brake tool that has the plate and the end that spins. Not sure why it was that way as I have never had issues before with any of the twist type of rear calipers.
Edit: Wonder if I roasted them from my track day since I did get excessive fade after the first session to the point of no brakes until halfway down even in the pits after cooling off for an hour.