Filtering feature doesn't work on columns made with arithmetic expressions of other columns

[aedelgado19]

When you load in a df to display, then add in a column to that df that is currently displayed via the code, the column cannot be used to filter.

Steps to recreate issue:

1. Display a dataframe in the pandastable GUI
2. Create column that uses other columns (I have a function that generates column data based on other column arithmetic and it successfully fills the column with data). The expression I used was (({height_1} / {height_2}) < 0.1) and ({name} == "Bob") which fills a new column "to_be_checked" with true or false values successfully for each row.
3. The new column appears in the manual filter dropdown, but if you use it in a filter (ex: filter for only "True"), pandastable code raises a KeyError since it cannot find the location with .get_loc(key)

shared images of error traceback -- the error is within pandastable code.