Cisco SPA525G phone not registering

Hope someone can help. 1 of 3 SIP phones (3 different locations) was working, but now won’t register. (Other 2 locations are working fine). Nothing changed (that i know of). Rebooted everything. No luck. Main router is connected to Netgear Orbi extender. Checked the port triggering, it is set correctly (TCP/UDF - 5060) on Orbi. Phone (SPA525G) is showing ip address in the menu/configuration, but all lights are orange and no connection to Asterisk server. What do you think it could be or do you know how I can debug or is there some sort of online documentation?

Thanks

Mark

determine if the phone is trying to register …

do the packets even make it to asterisk ?
does the register leave the phone ?

if both are yes its something in between

the asterisk console and sngrep are what I would suggest looking at initially to see if the requests are even making it to you

take a look at this as well…