I have several phones that have changed so that the user has to press the IC button with all incoming calls and then press CALL 1 button with all other calls. Before we used to only pick up calls under the CALL 1 button and did not have to press any buttons to answer.
Does anyone have an idea on what changed and what can I do to fix it?

Use the Auto Answer Feature codes, normally 361 & 360 by default, to toggle off/on.