Are breakout width values automatically generated when pasting Markdown into Confluence?

[Sumate Sivapornsatain]

Hi,

I am investigating a layout issue when pasting Markdown into Confluence.

Environment

- Confluence

- Microsoft Edge

- Markdown content maintained in .md files

- Markdown content copied and pasted into the Confluence editor

Problem

When Markdown containing fenced code blocks is pasted into Confluence, the code blocks are converted correctly.

However, some generated code blocks extend beyond the expected page layout, even when the source content is not particularly large and does not contain unusually long lines.

The original Markdown does not contain any width-related settings.

Additional observations

During troubleshooting, I noticed indications that width-related attributes may have been generated for some page elements. Examples include values such as:

- width: 760

- breakout width: 760

- breakout width: 1011

I did not explicitly define any of these values in the source Markdown.

Because of this, I suspect that width-related attributes may be generated during Markdown conversion or page rendering.

The issue has been observed in Microsoft Edge. I have not yet tested other browsers.

Questions

1. Does Confluence generate or store width-related attributes for code blocks?

2. Can breakout width values such as 760 or 1011 be generated automatically?

3. Could editor or browser size influence the generated code block width when content is pasted?

4. Is there a supported way to reset generated width settings and return to the default responsive behavior?

5. Has anyone experienced similar issues when importing or pasting Markdown into Confluence?

I found discussions about Markdown conversion limitations and table layout issues, but I could not find anything specifically related to breakout width values being assigned to code blocks.

Any information would be appreciated.

Thank you.