Hi. I had this issue as well. Please try 4200/2100 or 4400/2200 if possible. For some reason, the iGPU Memory Clock does 100s. Not sure if 25 or 50 or 75 works. I tried to increase by 100 and did not have that issue. So far, 3800/1900 works as intended, 4000/2000 works, 4200/2100 works...