How to use Panache query operation inside a loop in quarkus

Question

I'm try to get a information of a students belong to a school and each student has some n number of credits and these credits and in different entity

List<StudentsInfoDTO> studentsInfoListDTO = new ArrayList<>();
return School.findById
        .flatmap(school -> SchoolStudents.list("school",school)
            .flatmap(schoolStudentsList ->
                schoolStudentsList.foreach(schoolStudent-> getCreditsInfo(schoolStudent)
                    .subscribe().with(x->studentsInfoListDTO.add(x))
            )
        ); 

here i'm getting schoolStudentslist so i can get all students belong to the school but now I need the credits of the students as well so i wrote another method getCreditsInfo which will return studentsInfoDTO

public Uni<StudentsInfoDTO> getCreditsInfo(SchoolStudent schoolStudent) {
   AtomicInteger count = new AtomicInteger();
   return  StudentCredits.list("student",schoolStudent.student).map(studentCredits -> {
       studentCredits.forEach(studentCredit -> {
           if (studentCredits.credits.school == schoolStudent.school)count.getAndIncrement();
       });
       return new StudentsInfoDTO(schoolStudent.name,count.get());
   });
}

now when I run it, it throwing Mutiny had to drop the following exception: java.lang.IllegalStateException: Illegal pop() with non-matching JdbcValuesSourceProcessingState exception.

so how can i use panache transaction inside a for loop