In the Stage View, the alignment of the column headers like "Declarative: Checkout SCM" changes depending on how many builds have completed.
- If there is just one completed build and one in progress, then the column headers are centered. This comes from the browser default rule th { text-align: center; }.
- If there are two or more completed builds, so that the page also contains a warnings trend chart and a test results trend chart, then the column headers are aligned to the left edge. This comes from the rule th { text-align: inherit; } in https://REDACTED/jenkins/static/a8fa6dd6/plugin/bootstrap5-api/css/bootstrap-custom-build.css
In my opinion, bootstrap5-api should not be changing the styling of Jenkins components that are not deliberately using it.
I don't remember why Felix added that part in the CSS file (see https://github.com/jenkinsci/bootstrap4-api-plugin/commit/739b8d8a2c089d98a8a6a996ce17bbd76d5dcbee).
I think the risk to change it in BS5 is too high, I don't know what else will break. It should be much easier to provide the wanted alignment in the stage view plugin.