Having the same issue. The position returned by GetLeaderboardAroundPlayer is not the same as if you call GetLeaderboard.
Looking at the dashboard list. This appears to be returning some kind of filtered list based on score. We have lots of ties in our leaderboard.
In the list of all stats my player is actually 32, but when calling GetLeaderboardAroundPlayer for my player id and count of 1, the position is 23, which is the position of the first value equal to my value. Basically the first of the tied values in the master list.
So when say listing the top 25 entries, and then my entry position is 23. But I am not in the list at position 23. When my position entry should actually be 32 if gotten from GetLeaderboard