Cross hairs will never show up directly in the middle because the middle exsists in the third dimension now. It will also be misplaced due to the offset of the human eye. You would need to create a dynamic cross hair if you want it to be accurate.
As for the rendering issues if it’s not the mobile HDR that is the issue then try hitting the console key (~) on a WiFi keyboard. I have no idea why but when I make new projects this occasionally happens and that fixes it.