Connecting POTS lines to asterisk through channel bank

I’m having some difficulty with a POTS line connected to Asterisk through a channel bank. When I place a call to the phone number of the POTS line (POTS -> Channel Bank -> TE220 -> Asterisk) the CO doesn’t detect when the call is answered. From the calling side, the line continues to ring. I’ve tried having asterisk answer the call and then send the call to musiconhold. On the console I see that asterisk answers the call and starts music on hold, but from the calling phone (my cell phone) the phone is still ringing.

I have existing systems working like this with the only difference being that I’m using a Sangoma T1 card in the working systems. I am using the same version of Asterisk, the same channel banks, etc.

Anyone experience this?