Apex Legends player here.
I am also experiencing high latency and spikes on Singapore servers ever since I started playing 3 months ago, non of my other squad mates had any issues (they are on other ISP).
When it gets bad enough it's literally a slideshow, and was thinking to quit playing because of it.
Finally today I had enough, quick search on the internet and ended up here, did a tracert and the result exactly like others here.