my upload speed very slow. Fiber + TV install on 6/9/21 till today don't know why
Are you connecting directly to the ONR or through another router?
If using Asus router try enable/disable NAT acceleration, see if it makes a diff.
Have you tried restarting the ONR, or try switch off (disconnect) the set-top box temporarily to see if the upload is still slow.
Make sure your PC/Laptop not running any internet security (firewall) software, or some gaming LAN/ethernet optimizer software.
If still slow upload after checking the above, then need to contact 1688 liao.
By the way, didn't the Singtel tech have to run the speedtest before signing off on the work order?
Edit:
Also if you're testing on web browser, try running the Speedtest desktop app (Windows/MacOS).
Edit2:
Duh...noticed you're probably on wifi6 (AX) device? Try test on wired LAN if possible.