I just completed a flight and the Climb function worked for me. Note, I selected climb by simply mouse-clicking the Climb button on the mcp. If you are trying to use a joystick / TQ button or keyboard assignment, anything configured under the previous version will likely need to be re-assigned (search for ''les'' rather than 'LES' when looking for the commands).
Edit, perhaps I have misinterpreted your post. I can only confirm the INITIAL Climb command worked (setting pitch to match target speed), since I transitioned to a different climb mode rather than trying to select the Climb M or C
