Random Internet Connection Drops

I have been experiencing the same thing.  What you have written is almost exactly my situation, except it's happening mostly on my TV. This started a little over a month ago. I will be watching something and all of a sudden, it will just start buffering.  After a long while if waiting, I eventually check my settings (photos below, but these photos were taken when it was working) and instead of saying connected, like shown in the photo, it says, "connected with errors"  When this happens, I have to click on "forget network" and then I have to find mine, which is Champ, re-enter my password and connect again. When It is connected,  the signal strength constantly bounces between good and very good, it is never excellent.  When I called tech support almost two months ago, they said I was using an outdated modem and also sent a tech to my home.  The service tech said he found some problems with the outside and inside wiring, so he did something to those things, he replaced the modem and also told me I was connecting to my "guest account" instead of the main account, so he switched my Champ account to the 5 GHz and said I am all fixed up now.  It worked great for 2-3 weeks, but now we are back to it doing the exact same thing, sometimes several times a day.  This is very frustrating! 

On a separate note, I never knew until that day that I even have a main account and a guest account and I forgot to ask him before he left, how to find the guest account, what would it even be named, what would the password be and basically how to connect to it and when should I even be using the guest account?  I did tell him that day that we only use internet for our TV's and our cell phones and do not have a laptop or a desktop in our home at this time.  I'm wondering if the guest account is only for laptop or desktop use?

FRUSTRATED and CONFUSED