Marked version:
9.1.2

Describe the bug
The following content

Hashtags test
####
End of test

Is being parsed as

<p>Hashtags test<br>####<br>End of test</p>

Every other Markdown parser I tested will not output hashtags, so something like this is expected

<p>Hashtags test<br><br>End of test</p>

To Reproduce

marked.parse('Hashtags test\n####\nEnd of test')

Marked Demo

Expected behavior
Expected output is one that is produced by commonmark.js

Hashtags test

End of test