You can still step through debugger, but you need to use your mouse to click the buttons. If you are attempting to step through only with the keyboard commands, it is not expected to work because you are using a different keyboard command.
Thank you for the post.
howards is correct (thank you!) and for more information, please review the previous report here:
I'm not trying to use the keyboard commands, I'm trying to click the step in buttons to go directly to the next line with no response. Using exactly the same technique I can do it fine in FM13, but cannot in FM14