Hey kDelta, I'm glad it worked for you too. So, now that you are talking about passwords something clicked here. last week I set my MacBook Pro to unlock with Apple Watch. and the problem occurred for the first time on my iMac. The reason it works on the iPad is probably the watchOS being closer to iOS or actual iOS. I will try to disable this and see if I regain access. Apple needs us.

So, I had no password set on my SSD. Please elaborate what you did with password. I also received a warning in the "first aid" that I did: Performing fsck_apfs -y -x /dev/rdisk5s1 warning: container has been mounted by APFS version 1934.142.1, which is newer than 1934.141.2 warning: disabling overallocation repairs by default; use -o to override The volume Extreme 4TD was formatted by diskmanagementd (1934.121.2) and last modified by apfs_userfs (1934.142.1).

So the reason I did try the iPad Pro was that, as we all know apple is trying to do in the long run and why they introduced the APFS partition. Ever since Sierra they have expressed their desire to bring iOS and macOS closer and eventually to a unified architecture. In the end, the architecture will be symbiotic. This means that like iPhone, iPad, and Apple Watch we will see versions of the same OS tailored for the specific device. So I went on and tried. I'm glad to see it helps others.

Did you read my post from above? If you plug your APFS disks in an iPad Pro iOS can see the partition and you can copy your data safely and reformat the drive. If you need more assistance let me know.