Many leagues enter a starting handicap in event #1, which automatically carries forward from event to event until a "calculated" handicap is established.
This is by design...LM does this to save time for most leagues.

Note: If you have instructed LM to NOT calculate a handicap until a golfer has at least 3 scores...there is really no need to "lock" the handicap. LM simple uses whatever handicap you type in.
You only need to lock a handicap if you need to "override" what LM is calculating as the golfer's handicap for the particular event.

For more information, please refer to Handicap Examples