Actually, you already answered your questions with this.
I replaced one of the cards that is working properly with the one (Just running two cards) that isnt in that Pcie Slot and its showing the same issues (On slight movement from the fan).
And the title "
1070ti issue" said it all.
Try the card in a different slot, that's the last thing you can try.
Is your card came with a replacement warranty?
Unfortunately i have tried it all at this point; last thing i did was plug on the Pcie slot of the Mobo without the riser and by itself and it didnt work . It is a brand new card bought less than a month ago on amazon so i would be able to return it for a refund.