PGAdmin4 debugger - unable to call ltree functions

I have recently started working with the PGAdmin4 debugger and have
encountered a particular problem when testing my own functions that, in
turn, call functions from the ltree module. The sample code below
successfully runs in PSQL. However, it fails when run in the PGAdmin4
debugger. Specifically, the debugger generates the following error message
when it executes the first call to 'text2ltree':

ERROR: syntax error at position 0

CONTEXT: SQL statement "SELECT exists ( select 1 from TableLtree where
MyPath = text2ltree( MyArg ) )"

PL/pgSQL function testltree(text) line 5 at IF

I have successfully been able to use the debugger to walk through many of my
test functions providing they only use standard SQL variables. However, I
am unable to debug code that calls the ltree functions.

Is this a problem/bug with the debugger or am I doing something wrong? If I
am doing something wrong then can you tell me what it is?

Thank you,

Ian

Sample Code in a SQL file:

create extension if not exists ltree;

create extension if not exists pldbgapi;

create table if not exists TableLtree(

ID int

primary key generated by default as identity,

MyPath ltree

);

create or replace function TestLtree(

MyArg text

)

returns void

as $$

declare

status boolean;

begin

if exists ( select 1 from TableLtree where MyPath = text2ltree( MyArg )
) then

status := true;

else

status := false;

end if;

if status = false then

insert into TableLtree( MyPath ) values ( text2ltree( MyArg ) );

end if;

end;

$$ language plpgsql;

select * from TestLtree( 'a.b.c' );