Hi, thanks for posting.
The behaviour of the tree is set to always auto expand new tests when they are added to the tree (assuming that they match the filter). This is done so that you can easily see which tests are failing without needing to pick up the mouse and manually expand them all the time.
I would recommend using the filter to instead hide the ignored tests. Usually, they are off by default. There is a button on the Tests Window that allows you to show/hide the ignored tests.