Possibly a related problem, in version 922.g7f23d9d38, self-compiled on Linux:

For black-and-white pictures I like to develop the color version first, then open a second instance of the color calibration and move this above filmic in the development stack. Then I use this second copy as a channel mixer.

When I try to copy such a development stack to a different picture, the second instance of the color calibration is moved back to its original position and no longer sits above filmic; I have to move it back there again.