I have an older KX-T30810 Rev.3 and need to share one port with both phone types which the manual addendum for Version 3 says it will do. This option is enabeled for Ext 18 in programming.

Ether type of set works as it should when connected alone. Probelm is that if the SLT is connected and you connect the proprietary set, talk bettery is removed from the SLT so it cannot be used to make/receive calls but will ring when the Ext is dialed.

Is this how it should work. Am I missing something?