Same issue here. I am a professional photography and use external hard drives all the time with NO issues. I bought a new Macbook Pro M1 and now I cant access any of my drives but 1. I have no idea what is going on. I am able to install bootcamp and use the APFS for windows by Paragon Software mounter to access the drive. So it is definitely a probably with the new OS on the MAc. But even my older Mac's can no longer access the External Hard Drives that I have been using for YEARS!!! Anyone have a fix? Please. I CANNOT lose any of the data nor the organization. WE are talking like 10TB of info that CANNOT be lost.