I find those lines “interesting”:
[2019-12-11 15:51:07 +0200] notice/ClusterEvents: Discarding 'send custom notification' message for checkable 'l-ansible-master-01!Swap' from 'l-ic-s-01.mtl.labs.mlnx': Unauthorized access.
Those come immediately after the hard state change detection.
My guess is that this has something to do with the sms notification?