V4.75, fairly new install.
A weird issue, only resolve by a reboot. Wondering if anyone has had a similar issue and if there is another fix as I'm not sure if this will re-occur.

Intermittantly, an incoming call once answered would still get off-hook ring at the station that answered the call - while they were on the call and for the duration of the call. If this call was put on hold, the call would be on hold, showing flashing red on other sets, BUT would also ring the station group assigned to that line. While this happens, ringing calls on other lines would get one way voice when answered or cross-talk or would be disconnected.

This occurred across both TRMs, any line, but was intermittent when it occurred. Once I rebooted the system, the problem disappeared.