Model code generation error with Two model reference blocks both of which include one library block

Dear all, I met with a problem with the embedded model reference blocks. (1)I have one parent model (2) in (1),there tow referenced model: modelRef1 and modelRef2. (3) in modelRef1 and modelRef2,there is a library named with 'AddSum',the library block configuration is as a reusable funcion and the stored name is 'AddSum'.

When building the parent model, after modelRef1 and modelRef2 build completeness, during starting parent buid process, there is error poping up wih the conflicting usage of 'AddSum.h'.

It is ok to fix the problem to change the library code generation configuration page by selecting auto system code. but I want to put the library function into one file which seems clear to check code.

Is there anyone encountered with the same problem as mine? any comments would be appreciated very much.