Site Editor switches template when window width reduced or increased

[bobbingwide]

Description

While I was attempting to create an example of Classic Widget import I noticed that when I reduced the width of my window the template that I was editing switched to the front page.
When I re-adjusted the width it toggled back to the original template.

The problem occurs with WordPress 6.2-RC1 and Gutenberg 15.3.1
I do have other plugins activated and a custom FSE theme.

Step-by-step reproduction instructions

1. Open Site Editor
2. Add a new template eg page-widgets
3. Add an empty template part
4. Adjust the width of the window down - make it narrower
5. Notice that at some width the contents changes to the default template ( front page )
6. Adjust the window width up - wider and then narrower
7. Notice the contents toggles between the new template and default template ( front page )

Screenshots, screen recording, code snippet

A bit fast but it changes from page-widgets to front-page and then back again as I reduce the width then increase it again, then reduce it again.

Environment info

• WordPress 6.2-RC1
• Gutenberg 15.3.1
• Custom theme: Fizzie
• Other plugins are activated.

Please confirm that you have searched existing issues in the repo.

Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

No

[bobbingwide]

I reproduced the problem with TT3 and a template called page-widgets that contains

<!-- wp:template-part /-->

WordPress: 6.2-RC1 ( multi site )
Gutenberg: 15.3.1
No other plugins active.

[ndiego]

I have been able to confirm this in TT3 following the steps above.

cc @Mamaduka @ntsekouras @annezazu

[annezazu]

I can only replicate if Gutenberg 15.3.1 is installed. I cannot replicate if it's just 6.2 RC1.

For replicating with Gutenberg 15.3.1, I made a replay recording (which records the entire browser session) visible here: https://app.replay.io/recording/replicating-issue-49038--bb20f1e7-76d1-4e39-aff1-01059b0186f2?point=76910897249965681088535998507253760&time=27528 If folks would like access to replay to debug, ping me on WPORG slack (@annezazu there) and I can give you access to track down in case this is hard to find the root cause.

[ndiego]

Thanks for testing @annezazu. I can confirm that this does not occur in 6.2 RC1 when Gutenberg is disabled. I am going to leave it on the 6.2 Project Board and retest once RC2 comes out just to make sure the bug isn't inadvertently included in a backport.

[Mamaduka]

Does the template need to be created via UI or as a file inside the theme directory?

[bobbingwide]

Does the template need to be created via UI or as a file inside the theme directory?

I created the template with the UI. Step 2.

[Mamaduka]

I can reproduce the bug with Gutenberg 15.3, but not with the current trunk. This might be something that got fixed with other URL synchronization issues. See #48731.

[ndiego]

I am not able to replicate this use using only WordPress 6.2 RC2. Therefore, I am going to remove this from the 6.2 Project Board.

[Mamaduka]

@ndiego, can you replace it with the Gutenberg plugin's latest trunk?

[ndiego]

@Mamaduka nope, I do not see the issue with Gutenberg trunk either. So hopefully, this will all be resolved with 15.4 🤞

[github-actions]

Help us move this issue forward. This issue is being marked stale since it has no activity after 15 days of requesting more information. Please add info requested so we can help move the issue forward. Note: The triage policy is to close stale issues that need more info and no response after 2 weeks.

[annezazu]

Closing this out as I cannot replicate with 15.7 at this point! Happy to reopen if others can.