text: Title: [BUG]  UI shows incorrect node state
  Body: ### Describe the bug
  UI shows incorrect node state when two dataframes join.
  
  ### To Reproduce
  
  ```
  In [18]: df1 = md.read_csv('Downloads/ml-20m/movies.csv')
  
  In [19]: df2 = md.read_csv('Downloads/ml-20m/ratings.csv')
  
  In [20]: df1[['movieId', 'title']].merge(df2[['movieId', 'rating']], on="movieId").execute()
  ```
  
  The UI shows,
  
  ![image](https://user-images.githubusercontent.com/109642806/220543837-285dab42-6414-43bd-bf37-c497c8786dd0.png)
  
  Those nodes without color should be green.
  