MyBook will only mount if attached after Macbook Pro is running

I have an 8T MyBook which was working fine. I would leave it attached to my MacBook Pro when rebooting and the system would identify and mount it no issues. Then I found out about the sleep problem - and OK, I fixed that. But now, my Mac will only mount the drive if I attach it after the computer is already running - not from a clean boot.

My concern with this is I want to rebuild my Mac and am worried that it won’t find the HD in order to restore.

Steps I’ve taken (from this site):
Changed the Energy Saver to eliminate the sleep issue.
Deleted all WD software, including a file in the library and a password from system preferences.

I guess I’m ok having to plug it in fresh every time (even though it was working previously), but I’m really concerned the Mac won’t find it when I really need it during a restore.

I’m running Mojave and have not made any OS changes during this process - it just went from working to not…

Thanks in advance.

Hi tazman099,

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