Certified GKH Gardening Expert
Depending on the spot color, shape, and location, This could either be a fungal issue, or a deficiency. I am more inclined to say fungal issue. In this case, you can add some wettable sulfur to the soil to kill any infection, plus dolomitic lime to balance the pH.
This article will give you more information on the care of these: https://www.gardeningknowhow.com/ornamental/trees/sago-palm/how-to-care-for-sago-palms.htm