The issue is the same: there are periods of timestamps in the video streams that are out-of-order/discontinuous. This results in the video player freezing, because the frames it is receiving are later in the sequence; so, it holds the picture until it gets all of the rest of the frames. But by that time, in order to play the frame that caused the freeze it has to speed playback up in order to align the audio and video timestamps.
From my observations over the past week, I am 99% confident that these are all the same issue. The problems look to be related to the sequencing of the frames. However, whether that stems from Channels' remuxing the HLS TVE streams into MPEG-TS, or if the streams are messed up at the source, I cannot say.
(However, since this seems to be widespread across all internet sources, I think there is a bug in how Channels is remuxing the streams. I would revert back to a previous version, but I don't have anything earlier the 30 Dec. Perhaps a 27 Dec or earlier version could work.)
Edit: another data point: remuxing a problematic recording via Ffmpeg and dropping the file into Imports plays it back fine without the glitches. I find this is most likely the result of Ffmpeg reordering the problematic video frames as part of the remux.