NI-TimeSync 1.2 with NI-Sync Hardware Support

[GN]

I have equipped a PXI system with a PXI-6682H timing module in Slot2 and I edited the ni-timesync-nisync.ini as follows:

[TIME SYNC]
source.nisync.deviceName=PXI1Slot2
source.nisync.timekeeperGainAdjustRatio=1

Next, I have modified the original NI-Sync "Generate PPS and Wait.vi" example such as to replace the original while loop with a Timed Loop running on the 1MHz absolute timing source.

As shown in the attached snippet, at each iteration, the Actual Start timestamp (t1) is compared with the NI-Sync timestamp (t0) and the difference dt=t1-t0 is displayed.

Running this code from the LabVIEW project reveals a systematic difference that oscillates around 70 microseconds.

Should I consider this result as an indication that the synchronization of the system clock with the timing module through NI-TimeSync hardware plugin is no better than 75 microseconds, or there is something I am missing in my code that results in such difference?