Hi @laurentcharles,
When we request the items from Google using this query "sharedWithMe and trashed = false". The Google API responds with all explicitly shared items with you that are not “trashed”. It may be that Google’s own clients are adding an additional filter to this to narrow down the response even further.
My account doesn’t seem to have a discrepancy, so I am not able to experiment with a data set to determine what Google may be doing there.
Can you elaborate on what you mean here by “actual location”?