eiji2025

Thank you for your reply.

I performed some additional testing and was also able to reproduce the issue in WordPress Playground.

Although I cannot reproduce it 100% consistently, I found that the issue seems more likely to occur when copying and pasting an existing Custom HTML block.

In some cases, after pasting the block, the Custom HTML block appears blank in the editor. However:

• The HTML content is still present in Code Editor mode.
• No data loss has been observed.
• The frontend page displays correctly.
• Saving and updating the page works normally.

Browser testing results:

• Google Chrome: Issue occurs frequently.
• Microsoft Edge: Issue occurs frequently.
• Mozilla Firefox: I have not been able to reproduce the issue so far.

I tested using the following simple HTML snippet in a Custom HTML block:

<div style="text-align: center;">
    <p style="border: 1px solid blue; padding: 10px; display: inline-block; font-weight: bold; font-size: 40px; color: black; margin: 0;">
        Test <span style="color: blue;">Page</span>
    </p>
</div>

Since the issue can also be reproduced in WordPress Playground, it does not appear to be related to my hosting environment.

I have not yet found exact steps to reproduce it every time, but copying and pasting a Custom HTML block seems to increase the likelihood of the issue occurring.

At the moment, the problem appears to be limited to the Block Editor interface. I have not observed any impact on frontend output, page saving, or the stored HTML content.

I will continue testing and provide additional information if I discover a reliable reproduction pattern.

Thank you.