The fascinating thing is that it started at the same time and only ever affects the same relays.
Of all my servers, only 2 are affected. Each one has 40 exit or guard instances running.
Of the 40 guards, only one instance is affected:
E1AF5373E3240566B598FA481AD3860549F6168B
Of the 40 exits, only 4 instances are affected:
BEE071E521A47C740C9F6184FEBCF78BFF5F1275
24FDF4754BB3775A6D54E078DCBBCA43D7B1B07E
4A169C0A14E41F647D009EC49D28A3D11629DAF0
A398080A6A72F828DC4476DE45E28C5892CA1070