The options in your previous post look good as the usual suspects. Note that having Optimization enabled for the Compiler can affect the presence/accuracy of Debug Information, or it may be that sections of your code have been optimized in such a way that there is no matching line numbers for stepping.
We would really need an illustrative example to advise further. If possible, provide an example project with details of which source files/line numbers you are having issues with the stepping.
If you prefer not to post a project on the public forum, use the link below to contact private support and provide a link to this thread.
Regards,
Craig.