Opening file by double click and opening it through the Access are not the same. At the first case it would be a sort of private mode and therefore there are no surprise that no other users can use and change it. Opening files under Access must solve the issue.
What about your corrupt files, i would run “Compact and Repair” at first. It accessible from the Tools/Database Utilities menu. It might help.
Access while opening creates a .ldb file. It is not needed technically. Find it and delete, it can be hidden, therefore change your settings to see it.
If you have tried all the tips and no one helps, then maybe it is time for running a third-party. I would suggest Recovery Toolbox for Access https://access.recoverytoolbox.com/ it really can help in the issue and save your time and nerves.