Atlas is back now.
I've been looking into this and it appears that the jenkins WebAPI build job is auto building and deploying Atlas WebAPI whenever there is new code pushed to ANY branch of the WebAPI github repo, based on the github webhook. That rebuild and redeploy (even though the 'released' branch code it is building has not changed) is impacting Atlas availability.
There are frequent code updates to the 'master' branch but the jenkins job should only build and deploy Atlas WebAPI on the rare occasion when there is a new Atlas/WebAPI release (code pushed to the 'released' branch).
I'll be working on an update to the jenkins WebAPI build job to address this, but it will take a couple of days.