Logitec shipped a replacement set of speakers to me. That makes box #3. The difference this time was that the labels on the back of the speakers identified the unit as R720 not R710. The effect of these magic stickers is to make the speakers work perfectly. I am VERY happy. I recommend Logitec as a supplier because they didn’t flinch at shipping me a third set of speakers just to be sure I had a working set.
I finally have the warm and fuzzy feeling of owning some speakers that don’t get over-warm and are definitely not fuzzy.