Problem with Speakerphone
It is maybe some setting called Handsfree. On the phones that work, press Feature *0 and press the buttons on the right from the bottom up. The very bottom button should be handsfree/mute and the next one or two Intercom xx(x). Now check the ones that don't work and see if they read the same. I'm guessing not.
It takes system admin access to turn on handsfree per set. Check with your telephone system manager or installer for the programming.
Carl
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