Another day, Apple advised me to try with a completely fresh install, so I formatted my drive, installed a brand new Sonoma. I still get the error message.
Typical Apple... putting it on the customer to waste their day starting from scratch when they likely know it's a problem on their end but don't care because they don't make any money supporting third-party drives.
Are there any updates here, can't access my Lacie 2Big anymore... reading the same issue on multiple blogs, would getting hold of an Intel Mac be worth trying?