Yes, that was the initial change from Burgerhash V5 to Burgerhash V6.
With each previous update we also saw a 10% drop on average.

Now with Burgerhash V6 (ACE LIGHT) we have changed a few things, for example each of the 2 Keccak functions now has full 4 rounds of 72 bytes.

And we have an additional filler padding, etc.

But the important thing is, with each ACE LIGHT INSTRUCTION that gets added each 6 hours, the resulting hash drop is practically immeasurable.