Q.sylvestri palm problem.
I have a new transplanted sylvestri palm. healthy delivered weeks ago. since then I have seen problems on fronds with black moldy looking stuff. I am including picture ad no one has seen anything exactly like this. I am in Sanford FL. I would appreciate any help. Thank you.

Certified GKH Gardening Expert
This definitely sounds like a fungal issue. Usually, wettable sulfur will keep this at bay, no matter the fungus type. I would recommend adding this to the are, along with some dolomitic lime. This should bring your tree back.