Big Sur not seeing external (Seagate Backup Plus Portable 5tb (2r2apg-500 USB-to-USB-3) drive on Mac mini
Mac mini (Late 2014, 2.6 GHZ Dual-Core Intel Core i5, 8GB RAM) not seeing drive above but MacBook Air (Mid 2012, 1.7 GHz Dual-Core intel i5, 4GB RAM) does mount external drive & works just fine. (USB3 to USB2 hub to USB3 HD)
MISTAKE: I DID NOT DO THIS BUT UPGRADED DIRECTLY FROM APP STORE. ===> Both computers upgraded same week with same Installmac OS BigSur.app file.
Have WD 2TB and Toshiba 1TB successfully working on Mac mini (USB3 to USB2 hub to USB2 HD).