With the update to BlueOcean Aggregator 1.27.0 the amount of failed tests is no longer shown on the overview page. Previously that number was displayed right on top of the "Tests" tab on the BlueOcean headline.

That's a big step backwards especially if there's a pipeline with a lot of separate steps. Now you need explicitly click on "Tests" to open the test results to get the amount of failed tests.

Unfortunately I can't say exactly which version previously was installed but AFAIR it was a version equal or newer than 1.25.7.