Does XQN have some sort of code in it that tries to do us a favor by recombining small blocks together?
AFAIK I've seen this in nearly every PoS coin - it's relevant to the time it takes for a block to stake. For instance, when XQN still had 618 as the max subsidy I would stake blocks of ~5k XQN sit for ~2 days so when it staked they would become become ~5618 XQN blocks as opposed to two blocks ~2809.
Same thing has happened to me with TEK, HBN, HYP, etc, it just takes longer; likely related to a coins min stake age.