Latency Spikes in Overwatch

I’m located in Singapore but I usually play on Asian servers because most of my friends play there.

Haven’t had this problem in the past but recently, my game’s latency would spike to 700ms for about maybe 10 to 20 seconds before going back to normal latency at 105ms. It will about twice per match.

It happens when I am connected to Korean servers (I can tell I’m connected to Korean servers by looking at latency values and the teammates I’m matched with). Such spikes don’t happen when I’m on Taiwan servers (I usually have about 70ms latency on these servers).

I am pretty sure it’s not a hardware problem because I have tried both LAN and wireless connections with the same outcome; I only get spikes when I get connected to Korean servers.

Any suggestions on what the problem is?