It looks like Samsung fixed the issues it had encountered when it first started rolling out its Android 12-based One UI 4 update. The company is rolling out the update again to Galaxy S21 devices and the Galaxy Z Flip3 and Galaxy Z Fold3.
Even with a public beta process, Samsung ran into some problems during its initial release in November. Users were reporting poor performance, screen flicker troubles, and other bugs. Last week, Samsung paused the rollout in South Korea when some users raised problems with Google Play. Hopefully, the rollout now is a smoother process for Samsung users out there.
Source: The Verge