Q.The Upper Part Of My Madagascar Palm Is Getting Soft. And A Spot Is Starting To Weep.
It is an inside plant.

Certified GKH Gardening Expert
They go dormant in the winter so need very little water. It's possible it has been overwatered so replace the soil in the container and sanitize the container before refilling. Make sure the soil is well draining and has several drainage holes. The article below says you can cut off any diseased looking spots. (You may not be able to do that on top.)
https://www.gardeningknowhow.com/houseplants/madagascar-palm/madagascar-palm-care.htm