System include directory is not added by CMake 3.16.5 - c++

Question

I have observed the below detailed behaviour when compiling a C++ program with 2 different CMake versions:
3.10.2 (installed from default APT repository for Ubuntu 18.04); and
3.16.5 (installed together with CLion).
In the project the /usr/local/include folder is added to the include path (as a system include directory if it matters), through the ODB package:
include_directories(SYSTEM ${ODB_INCLUDE_DIRS})
Where ${ODB_INCLUDE_DIRS} is /usr/local/include for me.
When I use the CMake version 3.10.2 (from APT repository), the /usr/local/include directory is added to the include path correctly.
When I use the CMake version 3.16.5 (installed with CLion), the /usr/local/include directory is not added to the include path at all.
I could easily verify this difference by running make VERBOSE=1 and examining the compilation commands. This difference raised a compilation error for the project and I would be interested why do I experience this discrepancy between the mentioned 2 CMake versions? Was some default configuration changed between them?
I have created a MWE:
cmake_minimum_required(VERSION 3.4.3)
project(mwe)
include_directories(SYSTEM /usr/local/include)
add_executable(mwe main.cpp)
Where main.cpp is just a classic Hello World application.
Here are the interesting compilation commands (below I attach the complete logs):
with CMake 3.10.2 (/usr/local/include added correctly):
/usr/bin/c++ -isystem /usr/local/include -o CMakeFiles/mwe.dir/main.cpp.o -c /home/mate/Temp/mwe/main.cpp
with CMake 3.16.5 (/usr/local/include missing):
/usr/bin/c++ -o CMakeFiles/mwe.dir/main.cpp.o -c /home/mate/Temp/mwe/main.cpp
Running CMake 3.10.2:
>> cmake ..
-- The C compiler identification is GNU 7.5.0
-- The CXX compiler identification is GNU 7.5.0
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Configuring done
-- Generating done
-- Build files have been written to: /home/mate/Temp/mwe/build_3-10-2
>> make VERBOSE=1
/usr/bin/cmake -H/home/mate/Temp/mwe -B/home/mate/Temp/mwe/build_3-10-2 --check-build-system CMakeFiles/Makefile.cmake 0
/usr/bin/cmake -E cmake_progress_start /home/mate/Temp/mwe/build_3-10-2/CMakeFiles /home/mate/Temp/mwe/build_3-10-2/CMakeFiles/progress.marks
make -f CMakeFiles/Makefile2 all
make[1]: Entering directory '/home/mate/Temp/mwe/build_3-10-2'
make -f CMakeFiles/mwe.dir/build.make CMakeFiles/mwe.dir/depend
make[2]: Entering directory '/home/mate/Temp/mwe/build_3-10-2'
cd /home/mate/Temp/mwe/build_3-10-2 && /usr/bin/cmake -E cmake_depends "Unix Makefiles" /home/mate/Temp/mwe /home/mate/Temp/mwe /home/mate/Temp/mwe/build_3-10-2 /home/mate/Temp/mwe/build_3-10-2 /home/mate/Temp/mwe/build_3-10-2/CMakeFiles/mwe.dir/DependInfo.cmake --color=
Dependee "/home/mate/Temp/mwe/build_3-10-2/CMakeFiles/mwe.dir/DependInfo.cmake" is newer than depender "/home/mate/Temp/mwe/build_3-10-2/CMakeFiles/mwe.dir/depend.internal".
Dependee "/home/mate/Temp/mwe/build_3-10-2/CMakeFiles/CMakeDirectoryInformation.cmake" is newer than depender "/home/mate/Temp/mwe/build_3-10-2/CMakeFiles/mwe.dir/depend.internal".
Scanning dependencies of target mwe
make[2]: Leaving directory '/home/mate/Temp/mwe/build_3-10-2'
make -f CMakeFiles/mwe.dir/build.make CMakeFiles/mwe.dir/build
make[2]: Entering directory '/home/mate/Temp/mwe/build_3-10-2'
[ 50%] Building CXX object CMakeFiles/mwe.dir/main.cpp.o
/usr/bin/c++ -isystem /usr/local/include -o CMakeFiles/mwe.dir/main.cpp.o -c /home/mate/Temp/mwe/main.cpp
[100%] Linking CXX executable mwe
/usr/bin/cmake -E cmake_link_script CMakeFiles/mwe.dir/link.txt --verbose=1
/usr/bin/c++ CMakeFiles/mwe.dir/main.cpp.o -o mwe
make[2]: Leaving directory '/home/mate/Temp/mwe/build_3-10-2'
[100%] Built target mwe
make[1]: Leaving directory '/home/mate/Temp/mwe/build_3-10-2'
/usr/bin/cmake -E cmake_progress_start /home/mate/Temp/mwe/build_3-10-2/CMakeFiles 0
Running CMake 3.16.5:
>> /opt/CLion/bin/cmake/linux/bin/cmake ..
-- The C compiler identification is GNU 7.5.0
-- The CXX compiler identification is GNU 7.5.0
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Configuring done
-- Generating done
-- Build files have been written to: /home/mate/Temp/mwe/build_3-16-5
>> make VERBOSE=1
/opt/CLion/bin/cmake/linux/bin/cmake -S/home/mate/Temp/mwe -B/home/mate/Temp/mwe/build_3-16-5 --check-build-system CMakeFiles/Makefile.cmake 0
/opt/CLion/bin/cmake/linux/bin/cmake -E cmake_progress_start /home/mate/Temp/mwe/build_3-16-5/CMakeFiles /home/mate/Temp/mwe/build_3-16-5/CMakeFiles/progress.marks
make -f CMakeFiles/Makefile2 all
make[1]: Entering directory '/home/mate/Temp/mwe/build_3-16-5'
make -f CMakeFiles/mwe.dir/build.make CMakeFiles/mwe.dir/depend
make[2]: Entering directory '/home/mate/Temp/mwe/build_3-16-5'
cd /home/mate/Temp/mwe/build_3-16-5 && /opt/CLion/bin/cmake/linux/bin/cmake -E cmake_depends "Unix Makefiles" /home/mate/Temp/mwe /home/mate/Temp/mwe /home/mate/Temp/mwe/build_3-16-5 /home/mate/Temp/mwe/build_3-16-5 /home/mate/Temp/mwe/build_3-16-5/CMakeFiles/mwe.dir/DependInfo.cmake --color=
Dependee "/home/mate/Temp/mwe/build_3-16-5/CMakeFiles/mwe.dir/DependInfo.cmake" is newer than depender "/home/mate/Temp/mwe/build_3-16-5/CMakeFiles/mwe.dir/depend.internal".
Dependee "/home/mate/Temp/mwe/build_3-16-5/CMakeFiles/CMakeDirectoryInformation.cmake" is newer than depender "/home/mate/Temp/mwe/build_3-16-5/CMakeFiles/mwe.dir/depend.internal".
Scanning dependencies of target mwe
make[2]: Leaving directory '/home/mate/Temp/mwe/build_3-16-5'
make -f CMakeFiles/mwe.dir/build.make CMakeFiles/mwe.dir/build
make[2]: Entering directory '/home/mate/Temp/mwe/build_3-16-5'
[ 50%] Building CXX object CMakeFiles/mwe.dir/main.cpp.o
/usr/bin/c++ -o CMakeFiles/mwe.dir/main.cpp.o -c /home/mate/Temp/mwe/main.cpp
[100%] Linking CXX executable mwe
/opt/CLion/bin/cmake/linux/bin/cmake -E cmake_link_script CMakeFiles/mwe.dir/link.txt --verbose=1
/usr/bin/c++ CMakeFiles/mwe.dir/main.cpp.o -o mwe
make[2]: Leaving directory '/home/mate/Temp/mwe/build_3-16-5'
[100%] Built target mwe
make[1]: Leaving directory '/home/mate/Temp/mwe/build_3-16-5'
/opt/CLion/bin/cmake/linux/bin/cmake -E cmake_progress_start /home/mate/Temp/mwe/build_3-16-5/CMakeFiles 0