Post Editor is intermittently unresponsive to highlight/cut/paste, and cursor goes missing

[supernovia]

Quick summary

Several users have recently complained about issues with editing content in their posts. The complaints may show up as:

• missing cursor
• can't cut text
• can't paste
• can't replace a word

The problem is intermittent, but the editor is impossible to use when it happens

Steps to reproduce

This is only intermittently reproducible. The key is to edit a post with several paragraphs, and try to perform several typical edit functions: cutting, copying, pasting, and typing new things in between -- generally treating it like a text editor.

In my case, I triple clicked to select a paragraph, then used keyboard shortcuts to cut and backspace the block.

What you expected to happen

I expect the editor to just work; I should be able to cut and paste and replace words as needed.

What actually happened

The system is intermittently unresponsive:

locked.editor.mov

It seems some blocks are affected and others are not:
https://github.com/user-attachments/assets/3fea6c36-4dd3-414b-a1e1-d93fe7a6a6b7

Console messages if they're useful:

Impact

Some (< 50%)

Available workarounds?

Yes, difficult to implement

If the above answer is "Yes...", outline the workaround.

The error is to inconsistent to know if I've really got a fix, but so far changing to the code editor, editing some text, saving and going back seems to help, briefly, but I doubt most users would think to try that and I'm not sure if it always works.

Platform (Simple and/or Atomic)

Simple, and a customer reports the same issue for Atomic site

Logs or notes

So far I've only replicated on Simple, but as it's hard to replicate, that doesn't say much.

[supernovia]

This may be a case: 9214807-zd-a8c

[supernovia]

There are several cases in the forums; here's one ticket related to that:
9110306-zd-a8c

[github-actions]

Support References

This comment is automatically generated. Please do not edit it.

• 9214807-zen
• 9110306-zen
• 9178605-zen
• https://wordpress.com/forums/topic/desktop-site-no-longer-facilitates-editing
• 9267250-zen

[supernovia]

Two cases here: 9178605-zd-a8c

[supernovia]

Notes from a forums thread:

• They can edit for a while before the problem starts
• It happens across multiple browsers and devices (FF, Chrome, Edge on Windows and on Mac, even without extensions)
• Clearing cache doesn't help
• There are some console errors reported in this forum thread (I wasn't able to find similar errors in mine, though)
• Several users are reporting the issue in that thread.

[supernovia]

9267250-zd-a8c - this one is AT

[p-jackson]

The screenshots from the forum show the issue happening in the iframe'd editor (i.e. the URL starts with wordpress.com/post/...). And the video at the top of this GH issue shows the issue happening in the wp-admin post editor.

So it's clearly reproducible in both editor environments.

I haven't been able to reproduce myself yet, but will keep trying off-and-on. Ideally I can reproduce it locally so I can pause in the debugger to see where we're getting stuck.

[Robertght]

I tried replicating this on my end on Firefox and Chrome, using a Simple and AT site but had no luck yet.

I pinged @supernovia in Slack with a few questions I had p1736768138386089/1736766055.524549-slack-C01UW7SB411

[supernovia]

@Robertght @p-jackson the users in the forums seem to keep alluding to scrolling issues, which I thought must be some other problem, but now I'm wondering if they're related, since it does seem the post must have several paragraphs for the issue to occur.

[getdave]

I also attempted to reproduce this but was unable even when created a large post with lots of images and also throttling my CPU.

There must be some very specific setup to reproduce. @supernovia Are you able to open a support session or get a copy of the post content where he's having problems?

[cuemarie]

Hey @getdave, are you referring to a specific user whose content you're looking for? The forum thread in question has 11 different end-users reporting similar problems.

[supernovia]

@cuemarie if it helps I've got the video above; the cursor and basic editing functions just stop working. All of the users are experiencing that, from what I can see, though they aren't encountering it the same way.