While clicking on test in business central at project level, I can see it is showing reloading and after some time I can see test result passed and in duration section it was showing time around 1 second and some milliseconds, but  it took  around 2-3 minutes compare to system time.

I have created a sample project and created few test scenarios like 120 test cases and once I test it , shows the above behavior.And the same project works fine in RHPAM 7.7 .

As I starred test at 9:40 and it was loading during 2-3 minutes  , after 3 minutes at 9:43 I can see test case passed in window and duration I can see took around 1 second 521 milliseconds.

I have attached the screen shot.