Yes, I believe that is normal for your GPU fan to run fast during bootup. Once it boots into WIndows it should stop or slow down depending on the software that controls the GPU Fan.
This is a comment from a thread at Linustechtip.com: https://linustechtips.com/main/topic/437509-gpu-fans-go-mental-at-startup/
The high fan spin at startup is normal as there is no drivers running yet.
But once you reach the login screen it should settle up in few moments.
If not, just reinstall driver.
P.s, recheck AB settings