Posting as an FYI should anyone else run into this.  Experienced an issue with HS210 switches not connecting to my network even though I'd connected HS200's and HS220's previously.  I discovered that the HS210's would not connect while my SSID was hidden even with the correct credentials.  Had to unhide the SSID connect the switches and then rehide.  Everything seems to work fine after following that procedure.  Perhaps it something that has been fixed with a firrmware update?  Using an ASUS TM-AC1900 router fwiw.