Nighthawk RAX80 and SIP VOIP issues

Got a nighthawk router and comcast internet.  We went to a new phone system at work which is based on SIP.  We all use the same exact phone at work which is a Yealink SIP-T46S, and phones work perfectly fine plugged in at work.  When I took mine home last week and hooked it up it worked for a few hours, but then suddenly it stopped working and gave me a "Registration failed" warning on the phone.  Took the phone to the office and plugged it in and worked perfectly fine.

Next day went to work from home again and hooked phone up and didn't even work once this time.  Just that same registration failed message and lights were red on the phone for parking lot and conference and my login.

I went into the nighthawk router settings page and disabled SIP ALG, I verified that the router shows the phone in the devices list, even with the correct model number, and is even assigning it an IP.  I port forwarded the SIP 5060 ports to that IP that the router was giving the phone, restarted the router, restarted the phone, but didn't make any difference, still got the same issue.  I went through every setting I could see in the router and I cannot find anything else that I could change that would indicate SIP would be blocked.

I called Comcast and they said they do not block SIP.  I plugged the phoen directly into the modem cutting the router out completly and the phone worked fine so for sure something with these routers.  Got 2 other coworkers with netgear routers that same thing is happeneing to.  One has a Nighthawk as well.  Everyone else works fine.  

Is there some kind of hidden setting I am not seeing there?  The phone is getting an IP, it just doesn't seem to be able to talk to the SIP server when plugged into the netgear router.