I've only seen this issue happen twice now since we started using Mikrotik 8 years ago. Both times happened recently with different clients, one on Hex board and one on ARM both running 6.37.1. Everything will be running smoothly and out of the blue the PPPoE interface will become disabled, nothing else changes, and I have to manually enable the PPPoE interface again to bring the connection back up.
I don't think its some kind of hack because all router access services besides winbox are disabled, remote winbox access is only allowed from a our address range, nothing else is changed, the default login is changed, and the password is complex. If this happens again I may drive to the site and review logs but I have a feeling this is a bug of some kind.
Has anyone else seen this?