We have a SV8100 system running with UX5000 phones. (Upgraded the back end years ago and they kept their phones)

The system has ran flawless for years. Now I'm having misc phones loose their displays. Sometimes you can unplug them and reconnect and they'll come back. Sometimes they don't, but if you try them on another system. (Bench system at our office) They pop right on. I've replaced with new to them phones and within a few days they go out as well.

Anyone else see such a thing?