When using react-select with menuPostion="fixed" I've noticed a strange behaviour when trying to select an option after scrolling down.

The issue can be reproduced in this sandbox: https://codesandbox.io/s/react-codesandboxer-example-mxslt?file=/example.js

Steps:

• click on the select to open the options menu;
• scroll down the page (not the options menu) to the bottom (would be best if the select is no longer visible in the viewport);
• try to select any option that is not highlighted;
• the menu will re-render at different postion.

Is this an expected behaviour?

Here is what I found after digging into the code:

• when user hovers on an option in the menu, onOptionHover gets called

  react-select/packages/react-select/src/Select.js

  Lines 1142 to 1147 in 32ad5c0

  	onOptionHover = (focusedOption: OptionType) => {
  	if (this.blockOptionHover || this.state.focusedOption === focusedOption) {
  	return;
  	}
  	this.setState({ focusedOption });
  	};

  which calls setState;
• because the setState was called the menu is rerendered and freshly calculated offset is applied:

  react-select/packages/react-select/src/components/Menu.js

  Lines 519 to 521 in 32ad5c0

  	const rect = getBoundingClientObj(controlElement);
  	const scrollDistance = isFixed ? 0 : window.pageYOffset;
  	const offset = rect[placement] + scrollDistance;

Thanks,
Patryk.

P.S. Thanks for this awesome library!