Okay, I found that I had the same circumstance occurring when running LE. But here's the odd thing. I wasn't running any codecs! I have them installed on another RPi3 which is running OE versions (Isengard & Krypton). The only thing I can surmise is that somehow the latest release of LE is transcoding the Mpeg2 stream and thereby forcing the CPU to work like crazy and overheat(??) I tried different SD cards on the same RPi3 box and everytime I ran the HDHomeRun addon for our live TV feed, they all did the same thing (buffer and stop). But everytime I ran the SD card that has the LE 8.01 it would play the live TV feeds fine, albeit with an overheating warning/icon in the top right corner. Weird!
Just curious if this means that someone has placed code in the LE OS that allows the Mpeg2 licenses to be bypassed by transcoding(???!)