Crash lost my progress

So I’m not happy, I was going through the Cistern of Slaughter & managed to get all the way to round 5, only to have my game ctd, (submitted a report to Sony) when I loaded it back in I had to start the Cistern of Slaughter from round 1 again, I’m not happy, as I don’t understand why individual rounds are saved off like in the previous game & to be honest, i don’t feel like going back to it, what if I get another ctd?

Anyone else had this problem?