Problem is similar with the previous daily. I waited for new daily to be fixed but it still remains. Saving and loading times too long.
I tested on my file and found that it might be related to Corona Bitmap Shader.
First I converted all my materials to Corona Physical and all shaders to Corona Shaders. It tooks 58 seconds to save and 70 seconds to open.
Then i converted Corona Bitmap Shaders to Cinema Bitmap Shaders (just file), it tooks 7 seconds to save and 20 seconds to open.
(It was not more than 1 seconds with the Corona 11)
This might help you to fix problem.