I’m not sure on this one. Is the file actually synced, and the new content is on the remote now? It’s possible that a remote event triggered a local refresh which picked up the change prior to the local scan. It could also be that it fell into the local scan window at that moment.
Also, to clarify what I said above, the normal, expected interval for picking up local changes is 15 minutes. Depending on what else is happening on the system and when the change is made in relation to Agent startup, it can be longer (worse case between 30-60 minutes), but generally it should be a 15 minute interval.
Actually doing this is pretty easy with a simple find command. Here is an example from another user: