SoloLearn links

Question

Why many SoloLearn links do not work in a regular browser?

This, for example:
https://www.sololearn.com/learn/9660/?ref=app
Result is: Page Not Found

Answer 1

You can see it won't work when it ends with ?ref=app

Answer 2

Anything that links to a feed post, or a custom lesson outside the regular course won't work.
Site doesn't support them.

Answer 3

@cépagrave
Not true. Q&A posts and codes shared from the app work fine.
https://www.sololearn.com/Discuss/1835317/?ref=app
https://code.sololearn.com/WaYqkYRj6jTD/?ref=app

Update: The links aren't click able on the webpage but pasting them in a web browser they load without any issue.