Close Button of Show Columns Tool Is Unclickable

[JimCoates]

Expected Behavior

Expect that after opening the show columns tool, "x" button should be clickable to close.

Current Behavior

The menu still closes on click away, but the button is not clickable.

Steps to Reproduce (for bugs)

https://codesandbox.io/s/crazy-archimedes-93bnp?file=/src/App.js

Your Environment

Tech	Version
Material-UI	4.9.12
MUI-datatables	3.2.0
React	13.3.1
browser
etc

Running just the standard example from the documentation in code sandbox shows the button is not clickable.
I tried using older versions, it seems to not be an issue with v2.x

The library is excellent, thank you for taking the time to view this issue!

[patorjk]

Thank you for the report! Looks like this can be resolved by adjusting the z-index property of the button. I'll have a fix in version 3.3.0.

[patorjk]

Fixed in 3.3.0