Red buff reset

Upon my start of the jungle run as evelyn, I got a leash from a Misfortune and a Rakan on Red buff. Although I was on top of the monster, the buff refused to aggro on me and kept running away and reset. After taking Blue buff, I decided to return to Red buff to give it another shot and the same thing kept happening until a few minutes later. Or it could have been after I finished my first part of the jungle item. Upon finishing my full jungle item, I was not able to test if the buff would reset since I killed it before the bar would fully deplete.