When a build contains more than 20 commits, we truncate the
all_commit_details to the last 20 commits. You can tell if that is occurring in the UI on the build as it will say "Commit List":
In addition in the API response, you will find
all_commit_details_truncated set to
true when this occurs.
If you have automations that rely on information involved in commit messages you can send a final commit before you build with that information as we list the most recent commits in the response.