RE: Precision 3620 BIOS update issue.
A quick update on this issue. Dell TS offered to replace the MB since downgrading the BIOS back to v2.1.9 didn't work. I have decided to decline replacing the MB since everything was working fine prior to the BIOS upgrade and in the expectation that a future BIOS update will likely solve the issue. I'm currently successfully using an external USB RD1000 backup so I can wait until the issue is resolved to return to the internal RD1000.