Ported C++ project code does not stick across editor sessions ( crash after close )

I have a C++ project ported to 4.8 with the following problem.

Compiling the dll during the editor session works fine and the changes work as expected using the Play button, however a few seconds after closing the editor, a crash pops up ( something related to PhysX apparently, already submitted it a few times, i also have the latest PhysX system software installed ).

After starting the editor session again and immediately hitting Play, none of the gameplay changes seem to have stuck, even though the compiled dll from the last session still exists inside the Binaries/Win64 directory. I already tried to specifically compile with no editor open, thinking it may have to do with the dll being a hot-reload one, but no dice. Also deleting the Intermediate directory and rebuilding the project files did not seem to help. I always have to recompile the code again to make it work for the editor session only.

Anyone else got something like this ? Or any idea what else may be worth trying ?

Update, Not Solved :

Apparently this is even unrelated to the crash, which seems to be tied to the level.
When i change to a different map, compile the code, test it ( works as intended ) and then close the editor - i get no crash at all.
However after loading the project up again, the code-changes again have not stuck and i need to specifically recompile again ( no errors during compile either ).

Are there maybe certain directory-name setups that UE4 does not cope well with ? This one is “/projectName 4.8 - 2”.