I haven't seen this myself, but we have a 4L system with YeaLink phones, and I am told that several times when the users were "playing" with the system to get familiar with it, and were transferring one incoming call back and forth between two phones several times, that the display on the phones seemed to get out of synch with who the call was from.

I obviously need to do some tests myself so that I can try to duplicate the problem and let you know what steps are needed to replicate it, but I thought I should ask here while I'm testing to see if anyone else has experienced this issue, and if so, whether there is anything that can be done about it.