My company experiences regular occurrences of synced location disconnection from our Microsoft hosted SharePoint libraries (and also individual's OneDrive filestores).
What's worse is that there is no acknowledgement by OneDrive that anything is amiss and users continue to work with the cached version of files without realizing updates aren't being uploaded which results in some pretty horrible version confusion on documents being collaborated on. When sync is reestablished with those locations, outdated versions of files can somehow get synced up to SharePoint

This problem has occurred multiple times on many different computers in our organization and it's getting to the point that it's hard to trust OneDrive with our documents, but OneDrive has been made central to Office 365 so there's no good choice.
Because OneDrive is central to Ofice365 and SharePoint, it needs to be rock solid, dependable, and foolproof, which it is very far from currently.