I met the same problem. when app starts up, the first time i open a page, it will occur:
1. with small page, it's whole black;
2. with full screen page, partial black, and page offsets several pixels right-down .
then if i start another new page , it ok, no black block, no pixels offset;
My os is windows 10 with 4k screen, high dpi supported(scaling), gpu enabled, cef version is 84.3.10. Can see d3dwindow with spy++;
however, it's ok when using 3.2623.1401.0, with the same enviroment;
And also, it's OK if GPU is closed, but we donot want to disable GPU.
Can you give me some help?