I'll make a lot of progress on mission 8 with restarting from a checkpoint and advancing past it. I'll die, which is normal and the checkpoint will reload as expected. Eventually, I'll die and the checkpoint won't reload, and I have to start over again from the very beginning of the mission. I try doing a reload from last checkpoint when this happens, but it just goes back to the opening cinematics for the mission. This has already happened twice and this is very frustrating cause I'm so close to beating the game. What's going on here and how can I fix it?