Severely Low Upload Speed, Regular Download

For about a week now, I've been experiencing connection issues where others experience lag from data coming from me, such as in VOIP applications and games. I reset my modem and router and have been checking my speeds on various internet speed tests and have the same results:

Download speed is pretty normal, usually around 800Mbps (my plan is up to 940)

Upload speed is awful, 0.1-0.2 Mbps, while I'm supposed to be able to get up to 35 Mbps as per my plan.

I could really use any help with getting this issue rectified. 

As far as my hardware I'm using an ASUS AC3200 Router and an ARRIS SURFboard SB8200 Modem.

The connection issue is the same on all connected devices.