I've gone through the other similar posts and can't find exact issue:
Issue: A post with N comments will appropriately show "add / show N more comments" when reading the post & no comments are shown. BUT, it will show the same text when you click a link that navigates directly to a comment (i.e. from the inbox). So N comments are already shown (as if you clicked the "add / show" link already), and it still says "add / show N more comments" even though all N are showing.
Reproduce (on mobile): Click on any comment response from the top-right arrow dropdown to see. Can upload a screen cap if needed. I've reproduced this on answers with 7 and 10 comments, but but not 4 or less.
For me this link on mobile shows me "add / show 5 more comments" even though all 10 are comments showing. Clicking the "add / show" link shows me the comment dialog and still shows 10 comments. So in this case, the comment count appears incorrect as well.