Sharing: Query Loop block displaying sharing buttons on page editor but not on the live page

### Quick summary

A user has set up a Query Loop block on a page to display some posts: https://abenteuerinsglueck.com/siehbilles-memo/

They want sharing buttons to display below each post, and the buttons are actually showing up in the page editor: https://wordpress.com/page/abenteuerinsglueck.com/708 as it can be seen here: https://d.pr/i/Ag1ce1 but the sharing buttons don’t appear on the live page

### Steps to reproduce

1. Add a Query Loop block to a page set to display the entire post content
2. Enable Sharing Buttons for posts in Tools -> Marketing -> Sharing Buttons

### What you expected to happen

Sharing buttons should appear below each post on the page.

### What actually happened

Sharing buttons appear below each post on the page editor but not on the live page. (They appear as links on the page editor)

### Context

They are using the theme “Twenty Eleven”

I've tried disabling plugins, switching themes, etc... with no luck

I tried to replicate this on a test site but the sharing buttons don't appear below the posts if I don't set sharing buttons to display on pages too (The user doesn't want pages to display sharing buttons)

### Simple, Atomic or both?

Atomic

### Theme-specific issue?

_No response_

### Browser, operating system and other notes

_No response_

### Reproducibility

Once

### Severity

One

### Available workarounds?

_No response_

### Workaround details

_No response_

Start by reproducing the Query Loop setup with Sharing Buttons enabled for posts but not pages, comparing the page editor with the live page and the Twenty Eleven theme. Trace the Jetpack sharing-button rendering entry point and its Query Loop integration; done means buttons appear below each post on the live page without enabling them for pages.

Written by the indexing model from the issue text.