I'm an Overwatch player too, location at Klang, Selangor, package is 800mbps. Ping to TM is about 2ms, ping to Singtel SG is about 10ms, Overwatch normally is about 20ms~25ms, best I'd seen is 17ms, worst is about 28ms, but I can't really feel the different between 17ms to 28ms, even with my 144hz monitor.

So don't keep you eyes on the ping in game, just enjoy it, any ping below 30ms is barely noticable, I've seen ppl with 100ms ping but still 4 golds, lol.

What's the actual problem you are facing? Are you connect it with LAN cable or Wi-Fi?

Maybe you can try to reconnect to get another IP and test again, for example, I always use speedtest app to test the connection to Singtel server, some IP gave me 10ms+- ping, while other IP gave me 190ms ping.

The reason why I choose Singtel to test is because many server located at SG, from my experience I can tell almost half IP offered by TM are bad and the other half is good, so every time when I restart my router, I will reconnect again and again until I get the good IP.