Steps to reproduce in meta:
It only shows 5 topics.
It is exactly same in my own platform as well. There are many topics but it only shows 5. Is if possible to resolve this?
Correct behaviour:
If for instance, I mute the bug category, and later select the category from top left, I see all the posts, not 5.
I’m trying to repro this but I’m not sure I’m following your method 100%?
My step-by-step:
I realized what is happening. It only shows topics that has replies (or previously had replies but deleted).
I think it should show all topics in a category (even if it is muted) if someone explicitly clicks to that category.
I don’t click Top btw, I clicked the category name that I just muted.
The problem is that you have read all that topics and the status of the topic is now tracking and not normal.
You just see the topics, which you are tracking or watching.
Okay, I think I have been able to replicate similar with a test user here on Meta. 
I’m getting some slightly inconsistent results due to some of the #howto:training topics, but it’s pretty much -
When muted, ‘regular’ categories will display all normal (and above) topics when navigated to directly, whereas all those categories which are Parents will only display topics that are tracking and above (with the expectation that both types of category will behave in a similar manner).
Does that sound about right?
Yes, I think what you describe is correct.
