MacBook Pro (16-inch, 2019) 2.4 GHz 8-Core Intel Core i9 I have been running Big Sur beta 3 for a week and I had to back down to 15.6. The issue is when I plug in a external SSD or HD , the fans kick in to hyper drive, screen turns off then computer shuts down. All of this happens in about 2 seconds. Now if I leave the drive ( Samsung and or LaCie ) connected and the mac reboots everything is fine. But once I unmount and then reconnect the process starts over again. Anyone experiencing this ? Thanks Steve