I returned the car and there is a clue that the agents were wrong. The one guy that kept telling me that my Hertz number couldn't be attached and that I could choose from PC lot also had told me that I wouldn't get Hertz points from this supposed third party booking (again Autoslash through Priceline). Well, I got the points and it shows up in my account as a completed rental.

Makes me think I was entitled to PC lot despite what the guy was claiming.

Next time, I'll have a backup booked with AAA rage directly and I guess I'll message Autoslash that the Hertz number isn't getting added correctly.
​​​​​​It was sporadic before whether it would work get added by Priceline or not but this trip I made 5 different bookings and my Hertz number never got added properly.