• I've read and understood the contribution guidelines.
• I've searched for any related issues and avoided creating a duplicate issue.

Please give us a description of what happened.

After updating from 17.5 to 17.6 appearance of Select2 fields of ACF Pro in backend is broken.
This happens only with 17.6.
I can confirm it's not an issue in 17.5 and it has been reported that it's not an issue as far as 17.3.

Original report, with some feedback: here

Please describe what you expected to happen and why.

I expect custom styles for this plugin not to interfere with styles of other plugins.

How can we reproduce this behavior?

1. Install and activate Yoast SEO 17.6
2. Install and activate ACF Pro 5.11
3. Create a group with a custom field that uses Select2 (like Post Object with multiple values allowed)
4. Set the field group to appear if post type is posts
5. Create new or edit existing post
6. Look and try to edit the custom field just created in step 3
7. You'll notice the style is broken: like in this picture or in this picture

Technical info

• If relevant, which editor is affected (or editors):

• Classic Editor
• Gutenberg
• Classic Editor plugin

• Which browser is affected (or browsers):

• Chrome
• Firefox
• Safari
• Other

Used versions

• WordPress version: 5.8.2
• Yoast SEO version: 17.6
• Gutenberg plugin version:
• Classic Editor plugin version:
• Relevant plugins in case of a bug: Advanced Custom Fields Pro 5.11 (reportedly with 5.10.2 as well)

• Tested with theme: custom and twentytwentyone (not relevant)