I've experienced this same situation since trying to book a cruise on the website for 3 days. The only way I was able to get the cruise booked was by calling the toll-free number for Princess. I have also experienced the browser issue previously but I've been unable to book using either Chrome or Edge browsers even after both clearing the browser histories and restarting my laptop. I'm going out on a limb thinking it's PCL's IT department striking again. Bottom line is my advice is to call and book over the phone. Also, if you have a Princess Cruise Vacation Planner and are able to reach that person then that's another option.