Arithmetic columns get deleted when applying filtering

[aedelgado19]

If you make a column that is made out of other columns (ex: column 3 = column 1 + column 2) -- I have code that successfully makes this happen, and it fills a column in the display with data in every row -- it will get deleted upon filtering.

Steps to recreate issue:

1. load in df
2. apply filters to the df
3. add in your own column in the code (I have a button that fills df[new_col] with data and then updates the display so it shows up)
4. apply the same filters again, and the column you added in will delete from the display.