Door to Nova Prospekt won't open

Several things failed for me at the end of Sandtraps. I had to redo the area several times to get through it with none of these failing. 1. The rockets would bounce off the helicopters and then fly slowly and never hit them. This also meant I could not fire another rocket. 2. The antlion pods would hit the ground and slide, rather than penetrated. The antlions would ignore them. They also would not move out of the way when I walked into them. 3. Worst of all, the door to Nova Prospekt would not open, so I was stuck. Only after several additional playthroughs of this area did the door finally open.