Some saved pages lose spaces between words in text

Describe the bug

Some of Linguleo's pages are saved with missing spaces between words in the text.

To Reproduce

Steps to reproduce the behavior:

• Log in or sign in to Linguleo (choose English to learn and Russian as the primary language).
• Go to https://lingualeo.com/ru/course/14/task/30769.
• Complete the task if you haven't already (choose "eat", click "Далее", turn back). You should see the final text: "Sometimes I eat pizza for lunch."
• Save the page.
• Open the saved page and see that there are no spaces between words. The text is: "SometimesIeatpizzaforlunch."

Expected behavior

The saved page should contain text with spaces.

Screenshots

Original page:

Saved page:

Environment

• OS: Windows 11
• Browser: Firefox 149.0.2
• Version (SingleFile): 1.22.98

Additional context

What I've tried:

• Run in incognito mode
• Disable all extensions
• Reset SingleFile configuration

Not all such pages in Lingualeo have problems. For example, the page https://lingualeo.com/ru/course/22/task/1005 (choose "legs") saves as expected.