I have an iMac Pro (2017) running Big Sur with a Pegasus3 R6 Thunderbolt 3 configured for Raid 5 attached. i am running under Big Sur. I have the latest versions of both firmware and Promise Utilities software installed. As long as the Pegasus3 is attached to my iMac Pro I am unable to boot into windows by holding down the option key and slecting the Bootcamp volume. The Windows logo appears and then a spinning circle of white dots appears and spins forever without completing bootup. If I disconnect the Pegasus3 R6 system from my iMac Pro and go through the same procedure for booting into Windows 10, the bootup occurs promptly and without any problems. Clearly there is some negative interaction between the Pegaus3 R6 and booting into Windows 10 via Bootcamp. This probllem of booting into Windows 10 with the Pegasus3 R6 attached did not suddenly occur after installing Big Sur on my iMac Pro. Under the previous two Mac OS operating systems on this iMac Pro I have not been able to boot into Windows 10 via Bootcamp with the Pegasus3 attached. Note also yhat I have a Mac Pro (2019) with two Pegasus2 R6 units attached and there I am able to boot into Windows 10 via Bootcamp with no problem.The issue is specifically with the Pegasus3 R6 attached to the iMac Pro.
Can anyone suggest a solution to this issue.? Thank you in advance for responding.