Hi and Happy new year
I have 3 Harman kardon/cortana speakers and I experienced the same thing as all of you.
seems to be a cortana issue and Microsoft is discontinuing Cortana 01/31/2020 on IOS and Android phones in all countries.
except USA.
so there are glitches.
MS /Kardon sopposed to be send new firmware out.
when ????
I had some user issues but seems to be resolved, but what I
noticed is Cortana is Dumber not able read my email some of the simple things.
MS is working on moving her to Office 365.
hope this helps
ed