I have two well established cycads, one I put in ground under veranda with other palms and is doing fine and the other I put in tall pot with potting mix and most of the leaves are starting to go yellow and it's under same veranda. There is about 50% light to the pot and less to one in ground.
Yellowing leaves can indicate a few things; disease, insects and in this case likely a watering issue.
To much or to little.
These plants need to have well draining, moist soil but will die of root rot if they sit in soggy soil.
Here is a link to refresh you on the care requirements.