for dragable modal position of menu is wrong

**Do you want to request a *feature* or report a *bug*?**bug

**What is the current behavior?**
I am using modal in my code which is dragable. I am added table in modal and trying to open pop up on button click.But pop up menu position is far way from button location

**What is the expected behavior?**
Menu should be open at button click position

**Which versions of React, and which browser / OS are affected by this issue? Did this work in previous versions of React?**
current version 6.0.0

No files, tests, or entry points are named. Start by reproducing the issue with a draggable modal containing a table and a popup menu in the current React Contexify version, then inspect how the menu position is calculated; done means the menu opens at the clicked button's location.

Written by the indexing model from the issue text.