Roblox player data is overwritten by an older server

Issue
A player rejoins quickly and newer progress is replaced by data from the previous server.

Cause
Two servers can temporarily believe they own the same profile, especially when leave saves are slow or teleport flows overlap.

Fix
Use a session-lock token stored with the profile through UpdateAsync. Reject or wait when another live session owns the record, refresh the lock while active, and clear it during a successful release. Include a recovery timeout for abandoned locks.

Verify
Test rapid rejoin, teleport, server shutdown, and intentional save failures with separate servers.

Official Roblox DataStore update