Tiling/pixelation issues

It seems Xfinity's signal with Bally Sports Sun is not coming through correctly for me. I have constant tiling and pixelation. I've been trying to watch Miami Heat and Florida Panther games through this awful pixelation while at the same time paying $200 a month for service...a technician came 2 weeks ago, made some changes (great guy) seemed knowledgeable and it was indeed fixed...for about 3 days. Then, it started again. I called today for a tech. I have an appointment for next Saturday. I really need Xfinity to come through in a solution 😩  Is anyone else going through this with Comcast/ Xfinity??