Issue with Internet speeds

Hello,

I have been a cox customer for about a month now. I came from Frontier with an 18Mbps download speed and 1.5 upload. 

I have the Preferred service for 50Mbps and 5Mpbs and figured I would have NO issues streaming or anything like that. However, ever since I switched I haven't been able to stream anything without buffering. At first I thought maybe it's my wireless router so I went and bought a new one but has made no difference. Now mind you I didn't really have issues with frontier, I just wanted faster speed.

I contacted Cox chat support and his first response was your modem has been up for 26 days. I recommend restarting it every 15 days so it functions properly. Now, I work in IT, I have never ever heard that the modem on a cable modem has to be restarted every 15 days. That's ridiculous if you ask me. I don't know of ANYONE that does this. So he proceeded to restart my modem and tell me that if I have issues to contact back. 

To give you an idea, the other day there was a 300MB Xbox One update and that took me, no lie, about a half hour to download. Forget the day I had the big 4GB download. It actually started to download pretty fast then dropped to so slow it took close to 3 hours to download. That should've taken 25 mins at half the speed at worst. 

Here's a snapshot of what my modem looked like before he reset it Please let me know if anything seems off:

Thank you in advance