Linker issue for library dependencies

Hi everyone,
I have a little issue with my Cmake configuration.
This is the structure of my program:
I have two different cmake files:
1- for exec.out, the executable which links a static library lib.a.
2- for lib.a that contains some references to tensorflow-lite library ‘libtensorflow-lite’

In the lib.a Cmake file I inserted the ‘fetch Content’ to get tflite:

function(add_local_tflite)
	set(FETCHCONTENT_FULLY_DISCONNECTED OFF)
	set(FETCHCONTENT_QUIET OFF)
	
	include(FetchContent)
	FetchContent_Declare(
	    tflite
	    GIT_REPOSITORY  https://github.com/tensorflow/tensorflow.git  # Repository TensorFlow
	    GIT_TAG  v2.9.1  # Versione 2.9.1 di TensorFlow Lite
		SOURCE_SUBDIR tensorflow/lite  # Directory relativa del progetto TensorFlow Lite
	)

	FetchContent_MakeAvailable(tflite)
endfunction(add_local_tflite)

and

target_link_libraries(${PROJECT_NAME} PRIVATE tensorflow-lite)
target_include_directories(${PROJECT_NAME} PRIVATE ${tensorflow-lite_SOURCE_DIR})

No error for this part.

In the Cmake of the executable I linked the library:

target_link_libraries(myexec PRIVATE lib)

I have a problem with the linker because I get some ‘undefined reference’ errors for the object of tflite used in the library:

undefined reference to `tflite::FlatBufferModel::~FlatBufferModel()'
undefined reference to `tflite::Interpreter::~Interpreter()'

The executable code does not use any references to tflite.

what am I missing?