Intermittent Connectivity

My internet randomly drops, most often when doing high bandwidth activities such as streaming or playing online games. My modem has been reset by two different Cox representatives but not fixed, I have had zero problem with Cox for the entire year living in this apartment (Phx, AZ) until last night. Here is my conversation with a Cox representative that did not fix my problem but merely offered and suggested "I upgrade my plan." In the 3 images, you can clearly see my connection issue happening. How do I solve this?

https://imgur.com/a/rd2D7mM