Morning = few folks online. After 4PM and weekends = many more folks on line.If you have a cable TV modem - regardless if you actually watch cable TV, this is a pretty typical pattern.If you have a DSL modem, you have a single bottle neck serving a bunch of folks.If either of these are true - that you thought of a sat. link?You can search for a program called "Ping Plotter". This is a windows based product that allows you to see the ping times from your PC to some distance IP address. It should be pretty obvious where you slow-down is. It's a free program as long as you don't mind the "reminders". Might give your service guy an idea where to start.
It's the second option, and for some reason, after a couple months of flickering, the bottleneck has become a full blown choke point.One of my issues is cost - and irritation that the companies give me the telephone equivalent of a blank stare when I say that I don't watch TV and don't want it. I work from home. I watch Netflix now and again. That's it.
You may also want to check at the same time that the modem you're using is still on their approved/supported list, as 5 mbps is kinda slow even at your off peak time. I found out the hard way that the modem Comcast was renting to me was not on their supported list and I was getting 3 mbps instead of 20 while paying for 20 mbps and paying them for the modem rental. So, I went out and bought my own supported DOCSIS 3 modem and problem was solved and I got full speed.
It's an area problem. Which the tech seems to be slowly realizing.