OBB didn’t allow me to reserve Railjet seats? Am I screwed?

I am due for a trip on Thursday, March 14 from Vienna, Austria to Budapest, Hungary on Railjet Xpress 267 at 6:40 am-9:19 am. There was no option to reserve seats, and when I go to the site to reserve one, the train I booked says that no seats are available. However, I do have a link to OBB Live, which says that second class cars are either low utilization or high utilization. I am from the United States, so I’m not too well versed in rail travel. Will I still be able to board this train or will I have to book another one (I stupidly opted for the nonrefundable fare).