Rollout of the Beta is done in stages to allow load balancing on servers and the updates are pushed in groups. Depending on demand then could be few hours or a couple of days.
Nope i still havent got it. Despite enrolling yesterday. Ive never had this issue on my last s10 phone or s9.. Always got the download after enrolling. Now im still waiting after a day on my s21+ What s21 model do you have adzhork?