ok so i am having this issue on an asus x670e e gaming wifi. full custom loop. no alerts set. diablo4 just sends my fans into blinking red flash. so i got the solution, i hope.... i played for an hour with no trigger, flipped the settings back and bang ten minutes or less i was back to flashing red fans..
here try this.
open icue, click the settings gear thingy, click on software and games. top middle click to turn off 'game integrations'.. now below that about the middle of the page click on 'devices' tab and unclick all the boxes under 'game'
i cant get it to post a screenshot, but its easy to find. let me know if this works.