Steps to replicate the issue (include links if applicable):

• If I write:

Text
Text

Text

• It should be:

Text Text

Text

• But when I view the source code again:

Text
Text
Text

• Then if I click the "save changes" button:

Text Text Text

What happens?:

We find that there's no empty line between two paragraphs when we view the source code on pages on our website, and these paragraphs will turn into one paragraph if we click the "save changes" button.

Even though it still works that leaving an empty line to start a new paragraph, we still find there's no empty line when we view the source code again.

We once asked this question on Support Desk on mediawiki.org, but there's still no response now.
What should have happened instead?:

We often make an empty line between two paragraphs in source code.

Software version (skip for WMF-hosted wikis like Wikipedia):

• Website: United Earth Wiki, a website in Simplified Chinese and account needed if you want to edit pages
• MediaWiki 1.39.3
• PHP 8.0.26 (fpm-fcgi)
• MySQL 5.7.40-log
• ICU 50.2
• Lua 5.1.5