Variables are not available in Pycharm Debugger

I am using the PyCharm Debugger to view the variables of my script. It usually

I am trying to inspect the attributes of rulebased_device.subsystem by unfolding the corresponding dropdown menu. It works fine for rulebased_device.system, but with the former, there is a message Collecting data... and then the following interface shows up:

I have absolutely no clue what the issue might be here. I have googled it, but the results were that I should remove the content root in the Project Structure, and I don't think that's gonna make a difference except messing up my settings. When I run it in the Python Console, it shows me exit code -1073741571 (0xC00000FD).

I've resolved the issue. It was due to a circular reference. In a @property method, I reference the method itself instead of the private attribute prefixed by a an underscore (_).