Another strange night at my door, someone knocked and ran away like last week

Today at around 10 PM at night, the same thing happened again as last week. Someone loudly knocked on my door with fests and escaped again. Unfortunately, I didn’t manage to see who it was—I only noticed how the person quickly escaped. The stair railings were shaking right after, and there were some vibration sounds. In my opinion, he either grabbed them to run faster or accidentally hit them while running.

Right now I only have one suspect, which is my neighbor guy. Luckily, I don’t have any contact with him, and I don’t even remember when I last met him. It’s interesting that all this strange story started around the time that neighbor came back from a special military operation for vacation. Before that, I didn’t know about it—I only found out today that he had signed a special contract during his regular military service.