check the HKEY_LOCAL_MACHINE\\SOFTWARE\\Microsoft\\Windows Defender\\Exclusions\\Paths for excluded folders

reg query "HKEY_LOCAL_MACHINE\\SOFTWARE\\Microsoft\\Windows Defender\\Exclusions\\Paths"

HKEY_LOCAL_MACHINE\\SOFTWARE\\Microsoft\\Windows Defender\\Exclusions\\Paths
    Y:\\    REG_DWORD    0x0
    C:\\    REG_DWORD    0x0