Unless we read up all the threads and various sections in this forum we do not know of responses to our posts.
There could be an old post in a different section which I do not participate often, if someone respond to an older post in an older OP, I will not know of it.
Noted in PhBB supported Forum there is a "Notification" when any particular post of a member is quoted and replied.
The Notification is in 'red' and show the number of posts responded. Clicking it will produce the list of post responded by a specific member.
I suggest ILP install such a facility if it is free and available.