Just an update on where I'm at with this!
I downgraded one of the ESXi hosts from 6.7 to 6.5 Build 5310538.
I then modified Pool A on the MSA 2040. I added a second Disk Group to it. I then rebooted the esxi 6.5 host. (The vmware datastores for my esxi environemtn are located on Pool A.)
On reboot the datastores loaded correctly in ESXi 6.5! Dang!
This means that the problem is ESXi 6.7. Its not compatible the MSA 2040 GL225R003 firmware. Downgrading the esxi hosts to 6.5 is going to create a huge load of problems for the existing VMs (all built in the 6.7 environment), VM hardware version, vmotion, EVC mode....a right headache!