If you use the "#" char (which should have %23 as HTML escape) in your test descriptions, on the

<jenkins_root>/job/<test_job>/lastCompletedBuild/testReport/

view the link for that test (on column labelled "Package") does not parse that "#" char as %23.

Since in HTML URLs the "#" char has a meaning for inside-page anchor, the link for the test detail does not work.