I am new to PostgreSQL. Trying to understand the reason for erroneous results and would like to learn how to rectify it.
I have a students table. When I execute the query

SELECT stud_id, batch_type, subject, jdate ,subj_id, sdtime, subj_hours
FROM studs 
ORDER BY jdate DESC, subject DESC, stud_id ASC
LIMIT 15 OFFSET 0

I get the following correct result as expected:

When I try filter the results by adding WHERE condition in the query as below:

SELECT stud_id, batch_type, subject, jdate ,subj_id, sdtime, subj_hours form studs
WHERE subject < ’ Software Systems Development 5’
AND stud_id > ‘983e292ce1xy69c0’
ORDER BY join_date DESC, subject DESC, stud_id ASC
LIMIT 15 OFFSET 0

I get erroneous result as follows:

but I was expecting the following result:

Some rows are missed in the result. Can someone help me to understand the reason and how to fix it?