Degradation of service

I have been experiencing very frequent network dropouts all throughout the day and especially in the evening hours. It will either completely drop or partially drop and have massive packet loss. This occurs maybe 7-8 times on a good day and each of these bouts will last either 5 seconds or a few minutes. This has started happening a couple months ago and it has gradually gotten worse and cannot be ignored or have it chopped up to a random hiccup. I have recently replaced our modem with another from the xfinity store to see if it was just the modem and it has persisted. I have had a very similar problem over the last few years and I have had to get the fcc involved because of the lack of care I was receiving. xfinity techs have been out twice last year and determined that replacing the outside cable run and modem would fix the problems we have been having. It fixed the problem temporarily but unfortunately I'm right back to square one. I'd rather not submit another fcc ticket this time around and request a deeper look into my issue that has been plaguing my house and potentially my neighbors for years. 

On another note I have been trying for a few days to schedule an appointment but the ai assistant refuses to schedule me. It always deflects the blame to my device or router even though the xfinity app said my gateway was offline at the time of me trying to schedule an appointment.