My maneuver set is:
Kenkonken
Buffoon's Collar +1
Burana Earring
Karagoz Farsetto +1
Foirse Dastanas +1
Dispersal Mantle
My current theory is that the "Maneuver effects +" also has a chance to increase maneuver duration. Since I often idle in Midnights while my automaton is engaged, it's possible that due to lag (or whatever) the KKK aren't swapped in in time and that the 4 minute maneuvers I'm seeing are a result of both Burana and Midnights procing; that the 2 minute maneuvers are just Burana; and the 3 minute maneuvers are just Midnights.
Has anyone really tested this? Is it something else I've overlooked or never heard about? Am I going crazy or have other people seen this behavior too?