In an effort to get a 2 GPU solution working with my X399 tried putting my RX2080 in PCIE slot2 (TitanV in PCIE slot 1)

Seems to work, however, doubt this is a workable solution because there is NO clearance between my Titan V and the RTX2080, and the back plate of the 2080 gets quite warm!

Running out of options I next tried swapping my cards

TitanV in slot3
RX 2080 in slot 1

I seem to be making progress, as I can post, get into BIOS, however once I try and get past the Ubuntu GRUB menu I get repeating BAD DLLP and BAD TLP errors
arghhh!!!!!