404 error when pulling articles only by the module?!?

Hello,

I'm having a very weird issue causing 404 errors on Joomla 4 and I'm running out of ideas (already rebuilt categories and menus, as well).
Situation: There's a category - News (other categories too, of course, but I'm using this one as an example). Main menu has a News section - so far everything is pretty common. But..
- If I pull these articles as a Category blog, everything is just fine (but ugly).
- If I try to pull these articles through the Mini Frontpage module, e.g. call the module by its ID in an empty article, but DON'T have blog category, then the module can read and show the articles, but clicking on either of them causes 404 error.

And yes, I double checked - exactly the same URL can cause 404 or to work, depending if I have only the module, or the category blog as well.

Any ideas would be highly appreciated!
Philip

Hi, sure.
www.pchelp-bg.com/beta/lawfirm/novini - it pulls the content of the category, yet articles can't open.

I already have such menu. However, if I use exactly this approach, it would cause changing of the URLs on the front end.
On the other hand, this gives me an idea of one possible workaround... I'll write here with the results in a while.

OK, when setting the module for the same category blog (but set with 0 articles to show), the URLs work.
However, the module shows every time when even an article is open, so the next thing I need to figure out is how to hide the module when the URL contains the category but has an article open.