Hello Sdee, I am currently researching on this issue. As soon as I can, I will send you a message with my findings.
Thank you for your patience and understanding.
According to the engineering team, usually Intel makes a core BIOS and the OEMs will use it to build their BIOS revisions.
We recently released the microcode 0x829, however Dell would have to release an updated BIOS version with the 0x829 ucode included.
At this point this is outside of our control, please get in touch with DELL and check if the latest BIOS version included the newer Intel microcode.