External hard drive not visable with 2023 24-in iMac running Seqoia 15.5

Was that procedure you linked for viewing APFS Snapshots supposed to be initiated on my original iMac in order to find missing data and files? My new 24-inch Mac shows zero APFS Snapshots in the Disk Utility table on the bottom of the page, I think because because there are none since TM was never set up on it, due to The MyBook External hard drive where TM backups were saved from my old iMac is no longer visible in Finder, although I found and specified the last full backup from it when originally setting up my new Mac.

Thanks for replying. fsck does NOT show in the Process Name column.

No, Go/Computer only shows McIntosh HD and Network.

BTW, Favorites is missing from the sidebar as well, but I remember seeing it there previously. I don't even see it available to check in Finder Settings under "Show these items in the sidebar."

Does not show in Disk utility.

Today the "Favorites" Header is showing at the top of the Finder sidebar.

Yes, I have rebooted. Doing so again and then I'll try your command in terminal next.

Thanks, my wife has a laptop with Windows. I'l have her give that a try using Disk Management. Fingers crossed!

Thank you. I saw that they have a Q&A page on their website, so I'll check them out further.