I noticed that ms-be2050 showed some network reachability issues from icinga alerts, and after a quick check on the logs it seems that puppet/rsyslog/etc.. all started to show connectivity problems from ~ Dec 30th 10:24 UTC.
The only interesting thing that I found was the librenms graph for errors registered on the asw-d-codfw side, that clearly show a regression around that time (the other traffic graphs are also showing a change in behavior).