Is this a recent change where you’ve not yet done a makemigration / migrate?
It might be worth going into your database directly and verify that the table matches your model.
Also, when posting code, please enclose the code between lines consisting of three backtick - ` characters. This means you’ll have a line of ```, followed by your lines of code, then another line of ```. This will ensure that your code remains properly formatted. (This is really important with Python because of the significant white-space.)