I had this same issue on Stadia. I typically play Stadia with a Stadia controller on Chromecast, but happened to have my computer out. Going through the end of the Nautiloid sequence on my computer (using keyboard and mouse) played the cutscene as expected and I was able to save afterwards. Very strange indeed.
Just want to confirm this for any other Stadia users. In my personal experience, 3 times it failed to load the Ravaged Beach correctly when using chromecast and controller. Twice now it has worked perfectly when using chrome browser with mouse and keyboard. So it seems we have a way around it for now.
