When selecting the input for the dropdown, the expected behavior I think should be that the active_cell changes to the dropdown in focus. However, this isn’t the case:
I have created an issue for this on github:
I have the same problem.
I have a table with stock tickers in each row (column “Ticker”), I added a column with dropdown in order to allow the user to select an action for any stock that he choose (e.g. of dropdown options: “Buy”, “Sell”, etc).
But after the user selects the dropdown option the active_cell is located in another place and I can’t get the value entered by the user.
For my understanding if a user select a cell that has a dropdown, the active cell must be that selected cell 
There is another way to get the selected element without compearing previous data with actual data??
Thanks in advance.