The processor OCC firmware can call for fan speed increases if on-die Tj rise.
Where does that "Temperature Pcie" come from? Presuming it is from PCIe card(s), it would seem sensible that the BMC should monitor and adjust accordingly. Hard to imagine there is such a glaring bug in the BMC firmware, but worse has happened I guess.
Maybe Fan5 is supposed to cool the PCIe cards, but isn't working?