bfv screen resolution issue - show only top left corner in 4K 50fps setting

I can play other games (re2, re3, control, street fighter v, bloodstained, red dead redemption 2) in 3820 x 2160 60fps without issue. However, in BFV, when I select 3820 x 2160 50fps or 59.xx fps, it only shows the top left corner and the screen color is very different. It makes me very upsad as I spent the whole afternoon to configure the game and cannot get it working. 

I am running on a PC with i5 8th gen processor and RTX 2070 super. If anyone can help me, it is greatly appreciated.