can someone help me with my foxtail palm?! I have a crack in the middle of the trunk and it doesnt seem to be healing itself. I noticed it after the tree shed about 3 fronds ago and been hoping for it take care of itself, but it seems to be traveling up the tree. I have sprayed it with copper fungicide to prevent any disease. I purchased this plant about a year and a half ago with no visible damage, and hasnt had any damage since, that im aware of. I purchased another foxtail of a similar size at the same time that is thriving. The foxtail that is healthy has a trunk that is 4” in diameter vs. cracked-2.75”. I apply slow release miracle grow for palms, a little manganese sulphate, and a little muriate of potash every 3 months and havent had any previous problems. Is there anything i can pack the crack with to help heal the tree?

Diameter with crack

Crack with fresh bark from frond shedding

Healthy tree

Cracked tree. Maple in the background blocks some AM sun, but still receives plenty of rays.