I had something like that happen back in 2016, with an eVGA GeForce GTX 660 Ti and with Nvidia Inspector, found an Asus VBIOS on it! So to TPU, was exactly where I went! Then I found an eVGA VBIOS image with the 915 Mhz GPU clock, IIRC then I flashed that VBIOS on to it. Right after, it was like...