Some GPU's have fan designs that have 3 fans but only two are physically plugged in to the PCB,. meaning that one is daisy chained. So perhaps that's what you're seeing. In fact, you could inspect the fans leading off the GPU's PCB and see if one is split into two. Out of curiosity, which Strix card do you have? The one showing up for me is the Liquid cooler version's PCB. Can you parse a link to your card? A screenshot of what you're seeing on iCUE is also a good idea. Use HWMonitor to corroborate your findings.