That's not a bug. That's always like that on beta testing firmware because it's not considered a certified operating system yet. You'll have to wait until Samsung is done with beta testing and sends out the official firmware version, and then it'll work.
Hello, During beta program, the software is not yet certified by Google, and therefore Google Pay and other secure services may not work. We apologize for the inconvenience and will post a notice once it becomes certified by Google. You may try again at that time. Regards, One UI Beta Team
