Encoder running way too slow in version 2.7

We are streaming a news show for elementary. During live segments the stream works fine until we play a pre recorded segment. The videos have serious lag and video/audio match. We get a message that encoder is only running half of frames or running way too slow. Using a Black Magic Mini Ultra Studio with new Mac Airbook

Hi Karla, I’m sorry to hear about the troubles. I might have some suggestions based on the following information:
What format are the pre-recorded segments?
Can you give me the exact specs of the Mac you are using?
Are you recording and streaming at the same time?
What encoder settings are you using?