I have recently noticed that if I run tests in my pipeline and some tests are failing, that my pipeline will report the failed tests correctly, but won't stop. It happily continues with defective code, in my case deploying it to Staging.
I honestly would expect a CI/CD Pipeline to fail, rather than to ignore it.
What do I do: I run jasmine tests that write to an xml file and i make sure that this file is picked up by pipelines as described here: https://confluence.atlassian.com/bitbucket/test-reporting-in-pipelines-939708543.html
As you can see in the screenshot, it detects my reporting and correctly marks some tests as tailed. But the step itself does not fail.
I cannot find an option to change this behaviour.
