After further testing, I decided not to use a provisoning server. I factory reset the phone with 4.1.6. Logged into the web gui and only entered the SIP Server 1 address, port, user ID and password under Authentication, and the Display, address and label under Identification. Saved info...phone registered. Called the phone, pressed HOLD,....same 6 second delay!
This effectively ruled out any issues with the template I was using to configure the phone. This is as basic a setup as you can have. I still maintain this is an issue with the 4.1.6 firmware. I don't see how it could possibly be anything else.
again I can just remind you that I had done the same and it does not show this for me. Once Support gets all the details from yourself via your reseller we will be able to investigate this.
Are you testing on an Asterisk or Broadsoft system? What version? This may point to my server being part of the issue. I don't have another SIP server to test against.
I think I have found a solution! If I change the transport from DNSnaptr to UDP only, the issue doesn't present itself. I'm going to test all other functionality now, but can you tell me if there is any reason why I can't use UDP only for the transport? Do you know of any issues this would cause? Since you couldn't reproduce the issue, it appears that it's this setting in conjunction with my particular Asterisk server.
Thanks again for listening and providing feedback. It feels great to finally have this issue resolved!