Upgrade Firmware for Cisco DPC3825

I've been experiencing inconsistent download and upload speeds the past few days. I've done a few speed tests throughout the past few days and my download speed is, for the most part, fine and sort of consistent. Usually about 30-40 MBPS. As for my upload speed, it is very inconsistent and is constantly dropped. Making it difficult to load pages, watch videos, stream, game, etc. It sometimes will drop to as low as under 1 MBPS. It varies from high 20's to around 15-20, below 10's etc. I've tried resetting my router using the reset button, unplugging the power cord and even tried a hard reset, but to no avail. I've googled around and read some discussions and thought it may be that my router needs an upgrade on its firmware. I see that you guys do that automatically, but a few devices may fall behind here and there and I was wondering if that was the problem with my case.