Rune of Re-Origination

i have some question about this trinket

first, i just got the normal version 522 of the trinket, and i setup my weakauras to letme know when it procs and set up an ICD of 22 second,
my question/problem, is that sometimes in a fight i start the fight with the proc, and then, never proc again, and soemtimes i see that the trinket proc and proc again, and proc again 3 times ina row, without waiting for the icd

any thought??? or info?