RM1000e PSU fanat full spin from startup

[MHo]

I just completed my first PC build and used a RM1000e PSU. (Ryzen 9 7900x, RX6700xt GPU, ASUS X670e /wifi mobo, corsair H150i AIO cooler, RAM SSD etc etc)

I went through the motions of updating the BIOS/drivers on a Windows 11 Home OS.

At some point this PSU decided to ignore the fact that it is a Zero RPM fan which is only supposed to kick on at about 40% load and now just runs at full pelt from startup.

I've spent several hours searching the web for an answer/clue and didn't get very far. Tried opening a ticket with Corsairs little chat bot and am still waiting three days later.

This fan, supposedly a low noise fan for near silent operation, runs at about 40-42 dB straight out the gate. This is regardless of what I'm doing (BIOS, windows home screen, working, gaming, watching cat videos on YT)

So, either the PSU is defective in some way (temp sensor?), there is a setting that is incorrect (would not surprise me...) or it doesn't like me and wants me to yeet it out of a window.

Any ideas would be welcome