site editor, "all template parts" empty list in UI. Requires browser refresh

[rickers]

This behavior can be caused by:

1. display all patterns: Appearance -> Editor -> Patterns -> "All patterns"
2. display page 2. (the themeunittestdata has enough patterns for 2 pages)
3. select "All template parts" Observe the empty list displayed. Browser refresh restore the list.

[hellofromTonya]

Reproduction Report

This report validates that the issue can be reproduced.

Environment

• OS: macOS
• Web Server: Nginx
• PHP: 8.3.8
• WordPress: 6.6.2
• Browser: Firefox 131.0
• Theme: Twenty Twenty-Four
• Active Plugins: None

Steps to Reproduce

1. Log into your test site.
2. Go to Appearance > Editor
3. In the Design menu, select Patterns. By default, All patterns is selected and the first page of patterns displays in the content window.
4. Navigate the next page using the pagination at the bottom of the editor.
5. 🐞 Bug occurs. As no patterns display.
6. Refresh the browser.
7. Repeat step 4. 2nd page of patterns should render.

Expected Results

• Step 5: Patterns should render after navigating to the next page.
• Step 7: Patterns should also render.

When reproducing a bug:

• ❌ Step 5: patterns list should be empty, no patterns rendered.

Actual Results

• ✅ Step 5: Patterns render.
• ✅ Step 7: Patterns render.

I'm unable to reproduce the reported issue.

[hellofromTonya]

Test Report comment:2: 2nd page of Patterns > All patterns (without having to refresh the browser)

[hellofromTonya]

Hello @rickers,

Welcome to WordPress Core's Trac. I'm sorry to hear you are having difficulty with your site after updating to 6.6.2.

I'm not able to reproduce this issue (see test report).

Does this issue persist today for you?

If yes:

• Which theme are you using?
• Does it happen with a specific browser?
• Are there any errors in the browser's console and/or in the server logs?
• Is it an intermittent issue, meaning sometimes it works without refreshing the browser?

[rickers]

Hi! Thank you for looking at this... I am so embarrassed that I forgot to mention that this happens in "list" view, not "grid" view, my bad. Consistent behavior, always.

Upon checking my procedure, I've sadly left out some steps.

So, now the corrected procedure to cause the incorrect out put is this:
(changes in bold)

1. Log into your test site.
2. Go to Appearance > Editor
3. In the Design menu, select Patterns. By default, All patterns is selected and the first page of patterns displays in the content window.

3A. Select "table" view.

4. Navigate the next page using the pagination at the bottom of the editor.

4A. Now select "all template parts" (all template parts does not have 2 of parts)

5. 🐞 Bug occurs. As no template patterns display in the table (there is only 1 page of template patterns to display)

Steps 6 and 7, below, are informational. The bug appeared in step 5

6. Refresh the browser. (in 6.2.2 this worked, stayed in table view and showed list) (6.6.3-alpha-59007 switches back to grid view)
7. Repeat step 4. 2nd page of patterns should render.