I have both a Drobo 5D3 and a Drobo 8D, both connected via Thunderbolt 3 and got them working again after the problems of the initial Big Sur GA release. Today the 11.1 update was available and I upgraded. As soon as the Mac rebooted, I immediately got an error dialog with a big Stop Sign with an exclamation point and the text “macOS can’t repair the disk Drobo 5D3 (my name for it). You can still open or copy files on the disk, but you can’t save changes to files on the disk. Back up the disk and reformat it as soon as you can.” I tried connecting the 5D3 by USB but that didn’t fix it, so it may not be a Thunderbolt 3 problem this time. I am running Drobo Dashboard 3.5.2 and 4.2.1 firmware. It seems to be a coincidence to me that problems on both Drobos appeared at the exact time I updated to Big Sur 11.1. Also, the system and drive status of both Drobos show Good - no internal problems.