So in short,
PC directly Connected (via Cable) to Router -> 336ms PING
PC connected via USB Tethered Phone, which is connected (via WiFi) to the same Router -> 126ms PING
Now, what seems to be the issue ? I knew that WiFi increases Latency, but here is a different story overall.
Specs :
Core i5-8400
16 GB DDR4
Windows 10 Pro
1050Ti