Zephyr Workbench, a VSCode extension to manage Zephyr on STM32.
It enables users to easily create, develop, and debug Zephyr applications.
Main features:
Install host dependencies.
Import toolchain and SDK.
Create, configure, build and manage apps.
Debug STM32.
You can directly download it from the VSCode marketplace
For more details, visit the Zephyr Workbench
Same problem here with the STM3240G-EVAL. With one caveat. All was working find at one point then it just stopped. My memory is not too clear, but I think I tried a clean installed and it worked again briefly. Then busted. I confirmed that the board uses ST-LINKV2.