NBC buffering issues

I have Xfinity service both in Denver and Edwards, and I have NBC buffering issue -- video/audio buffering  pause that's lasts 15-30 seconds every 15-20 minutes of broadcast. I've switched to other multiple channels and there are no issues with them. It happens throughout the day, but the morning broadcasts are more frequent. Doesn't matter what type of show -- news, sports, they all have the same issue. Using X1 boxes in both homes -- have rebooted, replaced cables, etc. This definitely seems like it's a local NBC broadcast issue ... look forward to your reply.