Software Update Tool Finding available software 2020-08-03 08:28:31.504 softwareupdate[3628:137230] Creating client/daemon connection: 8DBD86DD-D6EF-40C5-9E6F-2FCF8162DACC Downloading macOS Big Sur Beta 3 downloading: 100.00% Failed to download & prepare update: Error Domain=SUMacControllerError Code=7722 "[SUMacControllerErrorPreflightPrerequisiteCheckFailed=7722] Failed to perform PreflightPrerequisite operation: com.apple.MobileSoftwareUpdate.preflight.error(Preflight):MSUPreflightErrorTargetIsNotSnapshotBooted(6) | The volume can not be used because it is not snapshot booted. > Current device configuration requires an alternate installer to perform the update.: [com.apple.MobileSoftwareUpdate.preflight.error(Preflight):MSUPreflightErrorTargetIsNotSnapshotBooted(6)|Unknown Error Indication|]" UserInfo={SUMacControllerErrorIndicationsSummary=|Unknown Error Indication|, SUMacControllerErrorIndicationsMask=8, SUMacControllerErrorIndicationsDescription=-> Current device configuration requires an alternate installer to perform the update., NSUnderlyingError=0x7fc8dd419ba0 {Error Domain=com.apple.MobileSoftwareUpdate.preflight.error Code=6 "The volume can not be used because it is not snapshot booted." UserInfo={NSLocalizedDescription=The volume can not be used because it is not snapshot booted., NSLocalizedFailureReason=The volume can not be used because it is not snapshot booted., MSUPreflightAlternateInstallerRecommended=true}}, NSDebugDescription=[SUMacControllerErrorPreflightPrerequisiteCheckFailed=7722] Failed to perform PreflightPrerequisite operation: com.apple.MobileSoftwareUpdate.preflight.error(Preflight):MSUPreflightErrorTargetIsNotSnapshotBooted(6) | The volume can not be used because it is not snapshot booted. > Current device configuration requires an alternate installer to perform the update.: [com.apple.MobileSoftwareUpdate.preflight.error(Preflight):MSUPreflightErrorTargetIsNotSnapshotBooted(6)|Unknown Error Indication|], NSLocalizedDescription=Current device configuration and target is invalid for install in the current state. Please try again.}

here the same with MacBook Pro 13 2020, any hint would be highly appreciated.