The classic Test Result view shows the correct test duration but in Blue Ocean, tests have always the "a few seconds" duration. And it's not because these tests took a few seconds.

core.test1  Error Details  Error DetailsAssertion: 'core_exited && exit_code == 0'h4.  Stack Trace  Stack Trace	1 min 26 sec	1
core.test2 Loading...	43 sec	1
core.test43 Loading...	1 min 25 sec	1
core.test44 Loading...	2 min 53 sec	1
core.test45 Loading...	37 sec	1
core.test84 Loading...	36 sec	1
core.test98 Loading...	46 sec	1
core.test101 Loading...	47 sec	1
core.test102 Loading...	46 sec	1