I posted a video a couple days after the first debate showing her light powered on before the debate began. His didn't. At the end, hers powered off. The light was controlled by someone away from the podium.
I of course don’t know, but she may have requested in advance to have hers on and he, his off.
I will say, however, it was just when Trump really went after Hill and Bill, about 10 minutes into the second debate that Trump’s mike started picking up his every breath again. Then it stopped. Possibly more dirty tricks IMO.