Pycharm auto completion, inspection and suggest system are malfunctioning on Django projects

Hi, I'm having a trouble related auto completion, inspection and suggestion system on Django projects on Pycharm.

For modules I wrote in my projects, those systems are working very well, but for Django base modules, such as django.core.management.BaseCommand, the systems are not working.

But the weird thing is it is working with no problems on the other project in the same environment.

What I've tried so far is following below:

1. updated Pycharm and restart the IDE

2. invalided caches and restart the IDE

3. reset Python interpreter

4. reset and enable Django support in Preferences > Languages & Frameworks > Django

I don't know what to do to solve this problem anymore. Please help me solve this!