The 5.13 has a bad problem in imac

After the Update for 5.13, my IMAC can not play the game cause the ping usually change to 500, and I need very long time to reconnect. However, when I use windows computer, it doesn't have this problem. What's interesting, when I play with my roommates, his macbook pro works very good, and my imac reconnect again and again. I have to download a new one, but the game still reconnect again and again.