Just a quick update: the RTX 3090 was replaced through warranty support.
Have a relatively new Aurora R12 with an RTX 3090. Everything was going great, games were performing great (Warzone) at around 120-130 fps in widescreen gaming. Temps would run in the lower 50's with MSI Afterburner keeping the fan speeds up to 100%. Then I noticed the temps in game getting up to 80*C+ and to the point where the game crashed. Used HWiNFO and the fan's RPM was 0. Opened the case to see if anything was obstructing airflow and found that the fans were only spinning a few revs and stopping even under load. Damaged card? Or something else?  I've reinstalled drivers, Afterburner, and checked other drivers...still no luck!
Aurora R12, RTX 3090 fans not spinning