CREATE OR ALTER trigger table_ad0 for table
active after delete position 0
AS
begin
  /* Trigger text */
  execute procedure proc(null, null, old.id, null);
end

Процедура:
create or alter procedure proc(
    p1 date = null,
    p2 date = null,
    p3 integer = null,
    p4 varchar(6) = null)
as
declare variable field1 integer;
... 
begin
  /* Procedure Text */
  
  --вот здесь работает
  insert into table_debug(field) values(:field1);

  for select t.field1, ...
      from table2 t
      left join table3...
      left join table4...
      ...
      where t.id=:p3
  into :field1,...
  do
  begin
    
    //а здесь не работает
    insert into table_debug(field) values(:field1);

  end

  exit;
end