This question is an exact duplicate of:
When a question got many other questions linked from/to it, there is a special page showing list of all those questions, e.g. https://meta.stackexchange.com/questions/linked/184642?sort=active
I just noticed while leaving it open, that the live refresh is active in there and showing "x questions with new activity" whenever there is new activity, even if in a question not linked to/from the original question.
I think the live refresh should be disabled while in that view, or filtered to load only questions actually being linked.