The same result for with SPACE and without SPACE

Postgres: PostgreSQL 13.7 on x86_64-pc-linux-gnu, compiled by gcc (GCC) 7.3.1 20180712 (Red Hat 7.3.1-12), 64-bit
Cloud: AWS RDS
pgAdmin: 4

SQL-1:-     with SPACE in WHERE clause
select * from BRONX.TEST_TEST_DETAILS_ALL_MCM where test_number = 'TEST4P20 ';

Result-1:
747   "AB "  "TEST4P20 "      " Max "     " IIH 1.8V Max "  "uA "  -405.000000 405.000000  "2023-06-14 01:12:17.714181+00"     
836   "AB "  "TEST4P20 "      "Max" "IIH 1.8V Max"    "uA "  -405.000000 405.000000  "2023-06-14 01:13:17.869917+00"     
906   "BI "  "TEST4P20 "      "PS16 Current (V7)"     "2.2V I DUT1-4"   "A "  0.001000    100.000000  "2023-06-14 01:14:04.95952+00"      

SQL-2:- without SPACE in WHERE clause
select * from BRONX.TEST_TEST_DETAILS_ALL_MCM where test_number = 'TEST4P20';

Result-2:
747   "AB "  "TEST4P20 "      " Max "     " IIH 1.8V Max "  "uA "  -405.000000 405.000000  "2023-06-14 01:12:17.714181+00"           "AMB"
836   "AB "  "TEST4P20 "      "Max" "IIH 1.8V Max"    "uA "  -405.000000 405.000000  "2023-06-14 01:13:17.869917+00"           "HOT"
906   "BI "  "TEST4P20 "      "PS16 Current (V7)"     "2.2V I DUT1-4"   "A "  0.001000    100.000000  "2023-06-14 01:14:04.95952+00"        

Please note in SQL-1 that test_number = 'TEST4P20 ' has a space and in SQL-2 there is no space test_number = 'TEST4P20' has no space.

Is it not a bug?
I do not want the above queries to fetch the same results.
I check the data closely which does has a SPACE in the table. In which case, SQL-2 should have fetched no rows.
Does anyone not agree on this?

Thanks,
Sarwar
From Greenbelt in Maryland!