Having some weirdness here. For objects with dictionary constructors, versions compiled against max-devkit generated Xcode projects don't work in 32-bit (but is fine in 64). I haven't yet tested against a cmake command line build.
The same code works in both 64 and 32 when using the legacy SDK. A minimal example is attached that should allow you to reproduce (unless this is a pathology local to my machine, of course).
dictcon.zip
Versions of things:
Max OS 10.12.6
cmake 3.9.5
Xcode 9.2
max 7.3.4