The Heart of the palm is well below where you have cut .
As short as those palms are , you'll have to cut at almost ground level to get into the heart . Other wise they'll just grow back .

This pic looks like what happens after a big freeze , or a big fire in Florida . Particularly Serena's will pop back like this soon after the event .

While your Trachy's do not actually have a Crownshaft , the basic construction is the same .