I didn’t get much time last night before I noticed so if anyone is willing to double check this I would appreciate it. The Hunter Captain was not dealing damage to any infantry units, nor was it applying the slow effect that also comes with it’s beam. It did seem to do damage to vehicles just fine although the slow was still not being applied for more than a second or so. After researching improved siphon the Hunter Captain seemed to have been performing as expected. I can’t remember what map it happened on, it was one of the desert maps during a 3v3.
This occurred on Xbox One in the US region.