The VSCode part of it is partly non open-sourced, so I don’t know where to look for logs there.
If it however obviously starts up when doing
then the VSCode side has a problem.
As expected, since when you run it on the command line, it’s completely disconnected from VSCode, so no breakpoints set there matter. It’s a new GDB session disconnected from the GUI.
This occurs when there’s a bootloader on the device. The only 2 known fixes for that is restarting debugging in VSCode (which you can’t yet do because the GUI part is not working for you) or removing the bootloader. See Problems starting debug session with jlink on feather M0 - #10 by RoSchmi.
As the CLI has no problem but VSCode has, please continue by opening an issue in Issues · platformio/platformio-vscode-ide · GitHub.