ltree and PHP

I've created the ltree extension

created a table with an ltree column called ltree_path

In php I can access the table, insert, update, delete.

but ltree operators don't work.

select count() from schema.table 
where 'A.B.C' @> ltree_path;

gives me a "could not determine polymorphic type anyrange because input has type unknown'

The same statement works just fine in psql, but not in PHP

If I change the statement to:

Is there someplace to 'create' or include ltree in PHP ?