chaining methods should be easier

versions
python 3.5
jupyter notebook v 5.4.1

I would like to chain methods in ipython/jupyter
I get suggestions on first method but when I attempt to chain methods I get ipynb_checkpoint.
See attached gifs for demo of behavior.

first gif I should get options like 'mean' but I get ipynb_checkpoint.

second gif I type two brackets and code completion fails entirely. I am hitting tab after [['J']] but nothing get suggested.

I should get method suggestions after typing a . but I don't.