Color calibration resets on its own

[LSVideo]

We have an iMac running our slides and videos. We have run a splitter from the monitor to our two side screens and to the main screen. We are running Keynote for our presentations.
Recently we have had an issue of the color calibration resetting itself and making everything we have on the screens up front very dark. Almost unwatchable.
Has anyone else had this issue and if you have can you let us know what you did to fix it?