We have a big problem at our company. More and more SPA922 devices are not working when we try to supply power to them via POE. The phones boot up until "Initializing Network" screen. Then the device start making a buzzing noise and the screen goes blank. The device does not react to any input. The device is working properly when powered with external adapter instead of POE.
We don't know the root cause of the issue, but it is happening with more and more IP phones.
Thank you for your help,