Necessary <br> tags are removed after switching to WYSIWYG and then back to Markdown mode

[mistris]

Describe the bug

I'm using https://github.com/markdown-it/markdown-it-deflist for definition lists.
After switching to WYSIWYG and then back to Markdown mode, necessary <br> tags are removed and in result definition list can't have multiple lines.
But it's not only about definition lists. Anywhere where I want to use <br> (e.g. inside <p></p> tags), it's not possible, because they are just removed from markdown after switching to WYSIWYG and then back to Markdown mode.

To Reproduce

1. Use this markdown:

### Definition lists (https://github.com/markdown-it/markdown-it-deflist)

Term 1

: Definition 1
with lazy continuation.<br>
Another line for this definition.

2. Switch to WYSIWYG mode
3. Switch back to Markdown mode

Expected behavior

<br> tag should not be removed.

Screenshots

Before switching to WYSIWYG

After switching to WYSIWYG and then back to Markdown

Environment:

• Windows 10 64-bit
• Google Chrome 83.0.4103.116
• ToastUI editor 2.1.2, 2.2.0, 2.3.0

[seonim-ryu]

@mistris It is difficult to confirm this problem by looking at this alone. I think the code of the markdown-it parser you are using has changed the behavior of the Editor. The default behavior is retained when you switch from WYSIWYG to Markdown when <br> is remained in the paragraph. Could you share the example page with something like the CodePen?

[bdevg]

Are you using react?

[mistris]

No.

[bdevg]

Oh