Nice windmill. I have the identical challenge. Not sure if the soil has settled over the years or if the roots have developed up higher on the trunk. Whenever I'm out in the landscape and have the correct tool I'll just pull some soil up around them.

This may just be a case of the tree pushing out the roots because it has no more room to grow underneath. I would mound more dirt and continue your usual routine. I live in Florida and have bought palms from some local nurseries here and seen this identical issue in container grown Palm trees, once planted they were fine.

Hope I was of some help.

-Fellow Palm Lover

Thanks everyone, I just got back from Florida and seen a lot of palms that had this and everyone seemed to think this was normal so I guess I will just mound some dirt around it.