The optics test works by over curing each of the steps of the ‘towers’ in sequence, so the bottom step is lasered once, the second step twice etc. with each additional layer having a increased layer power. The flattened shape of your tower suggests that there are smears on the glass running left to right which are refracting and spreading the laser light.
There are a couple of things you could try, one is to clean both sides of the window with acetone instead of IPA, the other is to buy a new window, I paid £50 for the ones I bought.
There are 4 screws holding the window in place. the two on the right side need to be removed, the two on the left side are hidden under the frame and accessed though holes in the frame. These should not be removed but just loosened so that the window can be slid out to the right.
Hope this helps, and just to add that I found get this window acceptably clean was one of the most frustrating thing I’ve ever done.