MacRumors published a story that Apple has released the sixth Beta of macOS Big Sur 11.3.

Apple Seeds Sixth Beta of macOS Big Sur 11.3 to Developers [Update: Public Beta Available]

Apple today seeded the sixth beta of an upcoming macOS Big Sur 11.3 update to developers for testing purposes, with the new beta coming one week after the launch of the fifth beta and more than a month after the release of macOS Big Sur 11.2, a bug fix update. Developers can download the ‌‌‌macOS Big Sur‌‌‌ 11.3 beta using the Software Update mechanism in System Preferences after installing the proper profile from the Apple Developer Center. ‌macOS Big Sur‌ 11.3 introduces more customization options for Safari, adding a way to rearrange the different sections on the Start Page like Favorites, Reading List, Siri Suggestions, Privacy Report, and more. Developers also have access to a new integration to develop features for the Start Page. 

Apple Seeds Sixth Beta of macOS Big Sur 11.3 to Developers [Update: Public Beta Available]