I have a customer who had their phone system moved from one location to another about 6 months ago.

When he is on a normal call and wants to put it on speakerphone, he puts the call on hold, sets the handset down, and then presses the held line. When he does that the call is automatically muted. If he presses the mute button, it makes no difference, the call is still muted. He can't get it off of mute. He has no handsfree/speakerphone button. Apparently this didn't happen before the phone system was moved. He tried on several phones, and it didn't change anything.

Any ideas?