Were the devices connected to a UPS or POE with some form of surge suppression?   I found, albeit painfully, that SIP phones, or other office electronics need to be on a UPS or form of surge suppression without this form of protection it is a bit lik...

The only thing that is missing is that often firmware updates are cumulative they do not download a fully functional firmware, (they don't re-create the wheel) Instead updates are often a firmware "delta" file.  This means the download only has those...

From your description it seems the extns that are nonconforming have some option or subscription activated which is causing the response.     I would confirm the firmware on the nonconforming units is the same as those on the conforming ones.  Also, ...

To determine if your router is blocking the transmission I would go into your router settings and set the ip address of the spa to be in the DMZ.  (Info about DMZ is Here)  Attempt to make a call if you have no problems then you have a problem with r...