Advanced Custom Fields Pro 6.4.0.1

Fix - Fixed PHP warnings logged due to incorrect parameter type for add_menu_page()/add_submenu_page()
Fix - Fixed bug causing WYSIWYG field to not keep line breaks
Fix - Fixed bug causing Email field to incorrectly invalidate emails with unicode characters
Fix - Fixed bug causing file type validation to fail in some cases
Fix - Fixed bug where newly uploaded or selected images do not contain custom preview size data

* Enhancement - Added 'position' setting compatibility for Options Page submenus.
* Enhancement - Visually highlight "High" metabox area when dragging metaboxes.
* Fix - Fixed compatibility issue between Block matrix alignment setting and the latest version of Gutenberg (10.6).
* Fix - Fixed bug breaking WYSIWYG field after reordering a child block via the block's toolbar up/down buttons.
* Fix - Added missing "readonly" and "disabled" attributes to DateTime and Time picker fields.
* Fix - Fixed bug incorrectly validating Email field values containing special characters.
* Fix - Fixed missing "dashicons" asset dependency from front-end forms.
* Fix - Fixed bug causing Review JSON diff modal to appear with narrow column since WP 5.7.
* Dev - Added label elements to Repeater, Flexible Content and Clone field's table header titles.
* Dev - Added new `ACF_EXPERIMENTAL_ESC_HTML` constant. [Read more](https://github.com/AdvancedCustomFields/acf/issues/500)

Fix - Fixed regression preventing blocks from loading correctly within the editor in WordPress 5.5.
Fix - Fixed bug causing incorrect post_status properties when restoring a Field Group from trash in WordPress 5.6.
Fix - Fixed edge case bug where a taxonomy named "options" could interfere with saving and loading option values.
Fix - Fixed additional PHP 8.0 warnings.
i18n - Updated Finnish translation thanks to Mikko Kekki