Many to Many relationship get all grouped records

I have the following three tables in a mysql database:

grades:

subjects:

grades_subject:

The grades table contains an id (primary key) student_id and quiz scores. A student_id can appear multiple times in this table.

The Subjects table is a simple list of subjects with a primary key.

The grades_subject table links the two with a subject id, grade id (The st_id links another table with student information). All three are a primary keys.

As you can see, a subject id can appear many times in this table as each student in the grades table can have multiple subjects. 20001 appears twice, once with subject id 1 and again with subject id 2 etc. Each subject id can also appear numerous times as numerous student_ids in the grades table can share one subject.

Im tyring to get all records in the grades table, grouped by subject id. So the result would be:

sbj_id 1...then all the students in that class with their respective grades. sbj_id 2... and so one for all subjects.

I have tried various solutions from this site and many combinations of different types of joins, groupings and also used select distinct. I either get duplicate values, or the correct records in the grades table but only 2 subject_ids, or student grades getting repeated for each subject and other inaccurate results.I have also tried subqueries.

This is the closest I have gotten to the correct results (I understand I do not neet the group by grades_subject.sbj_id in the below query, its just to demonstrate that it works):

SELECT grades.*, grades_subject.sbj_id
FROM grades
JOIN grades_subject ON grades.st_id = grades_subject.grd_id
where grades_subject.sbj_id = 49
group by grades_subject.sbj_id, grades_subject.grd_id

It results in all the scores for all students in that class which demonstrates that with my current setup I should be able to get what I am looking for with the right query or grouping. When I remove the where clause, I should get each sbj_id, and then all students in that subject with their scores, then the next subject etc. However, it will retrieve the scores for the first student in the subject, then duplicate those results for all other students in that subject as shown below:

Select Distint does not work, various join types do not work, selecting and grouping by ids in the grades table does not work including the primary id. Instead of listing everything I have tried that does not work...

How I can get my desired results with my current set up without changing my table setup as other tables and coding are built on it. The set up works well with all other types of queries that I need except when Im trying to get all student grades accross all subjects. If I must change the set up, please ellaborate on the simplest way.

Thank you.

@P.Salmon answered early on with:

"Can't be done with published data -perhaps grd_id in junction table has been incorrectly transcribed given it's the same as st_id and the table name is grade_subject but you do need a relationship to grade somewhere."

I was trying to make the db as efficient as possible by having only 1 linking table that serves as a many-to-many linking table to several other tables. The other tables were not shown in the original question as there was no need, but it is why there were duplicate columns in the grades_subject linking table because they served as foreign keys to other tables.

As @P.Salmon stated this will not work as much as I tried. I have redesigned the db and now have numerous many-to-many linking tables that link to a student information table. Maybe in the future, this can be added as a feature in MYSQL, as having just one linking table instead of many would be great if columns in other tables have identical identifiers.

I was not able to select the original comment as an answer.