Multi hits on dead opponents

I’m playing through the OC with no mods as a dual Kama wielding 4 fighter/11 monk (current level).

I have improved two weapon fighting, am wearing boots of speed and am using flurry of blows (which incidentally switches off after every fight which is irritating). I also have cleave (via free level 1 monk feat)

I get 4 standard main hand attacks, 2 off hand attacks plus one from flurry and one from haste. So I think 8 attacks per round.

I’ve noticed that the attacks seem to come in clumps through the round. Like 3 attacks at the same time, then another 3 a couple of seconds later, then the 2 offhand attacks at the end of the round.

The problem is that if I kill an enemy with the first attack of each clump, then the rest of the clump are wasted on the already dead opponent. And the cleave attack is also wasted on the already dead opponent.

So I can waste up to 3 attacks beating up a dead body! And unless I happen to kill my opponent with the last attack of each clump, I’m always wasting attacks.

I didn’t seem to have the same problem at lower levels, probably because with less attacks per round they weren’t getting clumped together.

In terms of repeatability, it’s basically every fight.