Downloaded the TheBay BIOS and downgraded (from 2013 back to 2011) the BIOS. Now I see the SATA 4/5 IDE disable/enable option in Chipset category. Lost a whole bunch of other settings though!
Disabled the SATA IDE option and booted into DSM 6.2.3 Update 2 with all drive attached; 3 HDD + 1 SSD with SSD attached to motherboard SATA. SSD recognized and needed quick repair. Fixed! Thank you.
Are your pic's showing the SSD you have problems with?
As I said, it is running in IDE mode, your DSM will only support AHCI drives.
Not sure what BIOS you are running, but in the one I use (TheBay),
to enable AHCI on all ports, you need to go to Southbridge Config, SATA 4/5 and disable sata 4/5 IDE mode.