Well, i'm having troubles with FFI on netcoreapp2 vs all good on netcoreapp3

[DllImport(LIB_NAME, CharSet = CharSet.Ansi)]
public static extern FFIExecResult ffi_exec_expr(FFIExpressionHandle ptr, FFIIdentifierKeyValue[] identifier_values, UIntPtr identifier_values_len);
I narrowed the problem to the function return type :
[StructLayout(LayoutKind.Sequential)]
internal unsafe struct FFIExecResult
{
[MarshalAs(UnmanagedType.I1)]
public bool is_error;
public IntPtr content;
public FFIStringHandle GetContent() => new FFIStringHandle(content);
}
Is there some other way to hack through this on netcore2 ?