In the UK 414 is PRS/MPD selection, 425 is CID trunks - however the CID format used in the UK wasn't supported on old systems (Compact II, DCS816, etc.), it wasn't even supported on the current Officeserv systems until v4.30 firmware.

As the trunk card works in the main, but not the expansion, chassis and the system was previously working the most likely cause is a bad/broken connection on the connectors or ribbon cable between the two chassis.