Hello, 
the new function c-ts-common-comment-indent-new-line has a different behavior 
from comment-indent-new-line in c-mode.
In a comment block like this:
/*
   Lorem ipsum dolor sit amet, consectetur adipiscing elit, 
   sed do eiusmod tempor incididunt ut labore et dolore magna aliqua
*/
M-j does not break the line or indent. The cursor simply stands still.
The attached patch handles this case.

Thank you.
V.