Variable explorer showing different length of a list

I have a list of 49 tuples. The variable explorer using Nbextensions, shows the length of the list as 536. I confirmed with print(len()) which gave me output 49.

Why does Jupyter notebook variable explorer show 536 then??

Start by reproducing the discrepancy with a list of 49 tuples in Jupyter Notebook using the Nbextensions variable explorer. Compare the explorer's reported length with print(len()) and determine which value is incorrect; done means the displayed length agrees with the Python result or the cause is documented.

Written by the indexing model from the issue text.