errors shown in cuda header files, when building with cmake

The inbuilt analyser in the editor shows me errors for .cuh and .h files. The errors are for example "Unsupported option '--exp-extended-lambda', Unsupported option ..". I guess, that creator tries to compile the file using clang for code warnings, supplies nvcc flags specified in the CMake file, and clang stops with errors. a regular build works correctly, which means, that CMake is setup correctly.

Here is a demo project:
CMakeLists.txt

cmake_minimum_required(VERSION 3.18)
project(cuda_test LANGUAGES CUDA CXX)
string(APPEND CMAKE_CUDA_FLAGS " --expt-extended-lambda --expt-relaxed-constexpr")

add_library(testlib kernel.cuh kernel.cu)
target_include_directories(testlib PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})

kernel.cuh and kernel.cu are empty. it's the same when using kernel.h. i've also attached the project as a zip.

The errors are shown, when you open the project in creator, and then click on kernel.cuh. kernel.cu does not show the error, but there is also no completion. after I added cu to the list of c++ sources in the mime types, it behaves the same as .cuh files.

the .cuh header also doesn't show under the Header Files. but that's a different bug and not so important.