Meridian Option 81 with Symposium in our 50 position 9-1-1 center using 2216's and Plant/CML VESTA CTI. Supervisor or trainer using Observe to remotely monitor are disconnected when a caller is transferred/conference to an external number like Poison Control or another PSAP, but can immediately re-observe and continue to listen. These transfer/conferences are done using the THF feature and using the 9-1-1 tandem to actually set up the call using speed or 10 digit dialing. Any ideas?