Unless you have some kind of notification or error that the internet has been lost, that's going to be tough if people don't notice. You could do something similar to the Security Flaw video with unbound forms, that way you are constantly re-connecting to the tables (or just use vba to constantly reconnect when opening forms or going to change data perhaps?)

I have internet connection detection but Access disconnects from SharePoint even if the connection was lost for a split second while SQL was running resulting in invalid keys being created, I can track the moment the connection was lost and would like to be able to restore it without involving the user , because when synchronizing tables manually, the access is completely reloaded, and this breaks the logic in the process of creating records

Once a connection is lost, all its properties are lost too, so there is no "reconnect" in the sense that you could bring back the same connection properties and reuse them.  You can only create a new connection and re-enter all the properties.  Also, you hope that when a disconnection occurs, your backend is able to roll back the changes that weren't committed.  SQL Server can do that; don't know about SharePoint using an Access backend.

thanks, I'll try

You got me. I know just enough about SharePoint to be dangerous. Lol