[Bug]: Social Link block within patterns are left aligned on preview, but centered on live site

[zaguiini]

Quick summary

WPCOM block patterns that are using the Social Links block are displaying that specific block contents on the left inside the preview, while correctly displaying them centered on the live site.

This only happens on patterns that are not surrounded by a Group block.

Editor	Live site

Steps to reproduce

1. Open FSE;
2. Choose a pattern listed inside Link in Bio, or one that has centered social links;

Verify that the social icons are left-aligned in the editor. Verify that the icons are centered on the live site.

What you expected to happen

Social icons to be centered in the editor.

What actually happened

Social icons are to the left inside the editor.

Context

No response

Browser

Google Chrome/Chromium

Simple/Atomic

Simple

Other notes

No response

Reproducibility

Consistent

Severity

All

Available workarounds?

Yes, easy to implement

Workaround details

It looks like we're using older block attributes inside the patterns:

<!-- wp:social-links {"align":"center","className":"is-style-default"} -->
<ul class="wp-block-social-links aligncenter is-style-default"></ul>
<!-- /wp:social-links -->

And this is the current structure when you add a Social Links block to the page:

<!-- wp:social-links {"layout":{"type":"flex","justifyContent":"center"}} -->
<ul class="wp-block-social-links">
</ul>
<!-- /wp:social-links -->

Doing a quick search in the posts on the patterns blog, it looks like there are 18 instances of wp:social-links \{.*"align that need to be replaced.

What reinforces my thesis about the old signature is that we're not even recognizing the settings inside the block editor. It's just straight set to the left, including layout settings:

[Addison-Stavlo]

Tested this today and can repro.

An example that will show this is the "Center-aligned header with logo and social icons" pattern.

cc @ianstewart

[zachspears]

I was also able to reproduce the issue. I have marked it triaged and normal priority.