UPDATE: Applied Windows 10 April's - Build 1803 update and it is booting faster now.
At this point knowing its narrowed down to just that Samsung SSD and other SSD in system is fast, I'd say try a reinstall of OS clean to Samsung SSD that's acting slow and if that doesn't fix it then avoid using that drive as a boot drive and be careful not to use that drive for important data storage if all of a sudden it fails to work completely.
I could do that but I was hoping there is a way without reinstalling the OS. I am positive it is not the hard disk itself failing since it is booting somewhat in acceptable time now after the update.
It's not the drives...somethin is hangin/slowin down boot...
All proper drivers installed ? ?...check device manager.
Also list all external devices being used.
Yes, all drivers installed correctly. How do I list external devices being used?
I do have the other SSD identified as a removable USB drive once I boot into Windows, though this issue has to do with My mobo BIOS as far as I read. In any case, it does not seem to be the root of the problem since it is booting faster now after the update.