All your posts are from the 15/07/2021 onwards.

According to the Activity calendar, last calculus was performed on the 14/07/2021, and the next will be on the 28/07/2021, so all your posts counts towards the current Activity window, and it is maxed at 14 Activity points per window, regardless of the number of posts you make above that mark within the current Activity window.
I’m not 100% positive, but I believe you may not see an activity increase on the 28th, but rather have to wait for the following Activity cycle.