I have 20ms ping in pubg game, but still experience no response time

Is that server within your radius? If so you will probably connect to it, only have the servers you want inside your radius with any other servers outside your radius. Move the location, adjust the radius size etc to achieve this - it doesn't need to be set to your precise location. They may be experiencing lag compensation, as their ping is so high so the game gives them an advantage to try and make it move even. More so to disable beam forming, mu-mimo etc rather than AX specifically.