Attempted with Mac OSX 10.11.6 using FMPA 16.0.3
and Windows 10 using both FMPA 15.0.4 and 16.0.3
The layout count on the overview at the top of the index.html page created by a DDR has been wrong (too high) in four out of six databases tested. The layout count on the Summary.html pages has been accurate in all counts.
To reproduce, simply create a database design report and compare the counts.
No workaround found yet.
It should be noted that one of the two files with a correct count was a brand new file created just for testing this issue. We have been unable to do anything so far to intentionally cause the count to become inaccurate. I would expect that newer files, or ones that have undergone few changes over time may not exhibit this problem.