This means two or more runners pulled the pipeline from the queue for execution. However, only one runner can accept ownership and execute the pipeline. This log entry simply means that the pipeline was accepted by another runner. It is not abnormal and is not indicative of a problem.
Are you running an outdated version of drone? We saw a similar thread yesterday where someone was running an unstable version of drone (drone/drone:latest) and it was outdated and therefore did not have the latest UI fixes.