In some cases when you have a parallel branch finish early, this won't show up as completed until the whole stage completes.
Looking at the following recording:
The right branch finishes after 1s, but doesn't show up as completed until I click on it.
The pipeline to reproduce this:
this sometimes does work. This also depends on the https://github.com/jenkinsci/blueocean-plugin/pull/557 being merged, which uses the new bismuth api.
There is likely some front end code that can be simplified.