MR Latency Measurements gives wierd result

I have been doing some latency checking on my MR816’s using a CEntrance latency test tool, and I get these results for 44.1 kHz:

Rate Buffer Latency
44.1 256 12.13
44.1 224 11.41
44.1 192 10.68
44.1 160 9.95
44.1 128 9.23
44.1 96 10.86
44.1 64 10.14
44.1 32 Can’t measure

Notice how the lowest round trip value is at 128, and then it gets higher at 96 and 64. The tool from CEntrance measures by sending a pulse on a round trip from out to in on the MR (you have to physically connect the out to ins). And its measure results are stable at those values recorded above, so i can see only one conclusion:
The MR inserts extra safety buffers at low buffer settings or…?

Has anybody else done this test and come up with same result or different results?

If anyone is interested in using the latency tool it can be found here:

I have the same result with mine