Massive Bufferbloat and intermittent Issues over the past month

Just over a month ago I started having really bad rubber banding and pack loss while intermittently while playing online games. I reported the issue to xfinity and they sent out a technician who replaced the cable in the wall and my gateway which was about 5 years old. This issue has not resolved itself, customer support says there are no issues in the area so I'm stumped.|