It looks like Wild Explorer is patching TreeFeature to enable growing palm trees on sand: https://github.com/DawnTeamMC/WildExplorer/blob/1.16/src/main/java/com/hugman/wild_explorer/mixin/TreeFeatureMixin.java

Which, as it happens, is exactly what we do as well: https://github.com/TerraformersMC/Terrestria/blob/1.16.3/src/main/java/com/terraformersmc/terrestria/mixin/MixinTreeFeature.java

It would probably be best to create a tiny little compatibility module that handles the injection, eliminating the redirect conflict. Perhaps a Terraform module?

Fixed in the latest releases of Terrestria and Wild Explorer