On Tuesday (May 1, 2018), I noticed some issues with recordings made from WLS (ABC) in Chicago.
On "The Middle" and "blackish", I could only play the recordings. I could not FF, REW, skip, review, or pause! I just got the 'no' symbol. The timebar said 30 minutes, but never went beyond 0. Closed Captioning did not work. Other recordings made at the same time are fine.
This is probably not a Comcast issue, but again, there are street noises leaking into the audio. During quiet scenes, I could hear truck and car traffic. I think this was an issue a year or so ago, and now it seems to be back.