Do the calls cancel at the exact same time? If they do, there must be some continuity between CCR & UCT/DCT, maybe a short or jumper in UX or DX relay or base. There should be no continuity with both UX & DX dropped or with them removed. If the far call cancels early, I'd be curious if it cancels before CR picks, maybe something jumping around The CR contact. You may want to block CR contact 1 from closing to prove that the call is dropping through that path. CC is a black 32vdc relay right?
