Loud static noise when other end hangs up

[Ivanb10]

I am having an issue where one someone hangs up, there is a loud static noise at the end. The phones we are using are Polycom vvx 500 version 5.9.43247. I understand these are EOL but if someone can provide some help or point me in the right direction to fix this issue would be greatly appreciated.

 

[Alejandro_3CX]

Hi, I wonder if you have the same behaviour when using a supported IP phone or 3CX Application?

 

[Ivanb10]

I tested on the 3cx app and it did not do it. Also as I said before, I understand this is in EOL so there may not be much support on this, but it someone could just point me in the right direction.