Answering my own question about Xcode breakpoints not working, you have to configure the remappings in your .dSYM files. The tutorial below does an amazing job in stating the problem and walking you through on how to solve it.
The tl;dr is that you have to generate .plist files that map the build source files where the engine was compiled in and the source files that are in your machine.
This other thread also talks about the same issue: