The problem occur while you’re using the MOCOI or normal traffic.
If for MOCOI, since this command is software to monitor the voice in GS. Please check your BL or setting. If for normal traffic, that maybe miss match for CIC no.
e.g. you set TS1-TS31, is CIC 1-30.
But your other partner setting is CIC 2-31. You may find 2-30 is idle but in fact, is silence. Due to signalling is up. But the phyical TS is miss match. Hope can help you.