We have a customers UC520 that lights up the CO Line when a call is coming in, but it is a solid red light (doesn't flash). This lasts for about 10 seconds, and then it goes dark, lights up again, and then rings like it normally should (and the corresponding button flashes). If no one picks up then it goes to voicemail as normal. Also, if the line is picked up while just solid red, it does connect the call just fine. According to the customer this happened abruptly one day, and is only on the first CO Line (they have 12 total).
The system was configured completely with CCA 3.0 and is running software pack 8.0.1. I checked under CCA to make sure the right CO Line was there, and everything looks fine. I tried deleting the button and readding it on a phone, but the same issue occurs.
Any thoughts as to why this is happening?