I am new to postgresql. Trying to understand the reason for erroneous results from Postgres 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 form studs
ORDER BY jdate DESC, subject DESC, stud_id ASC LIMIT 15 OFFSET 0

I get the following corect 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.

Can someone help me understanding the reason for the erroneous result and how to rectify this issue please. Thanks in advance.