the type of corruption you describe is typical of multiple users sharing the front end.
Everything you have said up until your last post indicates this is what has been happening.
You are now saying each user has their own copy on their local machine. So perhaps something is happening when you distribute an updated FE to your users
My guess is that even if they have their own copy, they (or some) are still using the FE you have on the server. To confirm, suggest you remove the FE from the server.
Or if you are up for some coding, when the FE first starts it checks if its own path is a local one or on the server. If it is the server path, the FE closes.
As to other reasons for corruption, perhaps you have some code which messes up the vba (although it would also mess up your own copy as well) - so ensure you distribute a .accde file to your users, not a .accdb.
Other possibilities include users connecting to the backend via a wireless connection - although unlikely to corrupt the front end, it could corrupt the backend