Apologies => I just copied this comment into another thread (Running lap times not matching watch), which seems to be even more fitting in the description.
As I donât want to add another thread and have not found a better one:
I find it is a more than a little bit annoying, that there is (the last three runs exactly) 10 seconds difference in the lap-time of the first kilometer between the watch (SSWHR) and the app (the app is faster by 10 seconds), all other kilometers differ only slightly and only sometimes (mostly a maximum of 1-2 seconds).
Running distance is between 10,x and 13,x kilometers.
The overall distance and time (etc) is identical.