When you share a vault with other people, according to my google searching Cryptomator will save the conflicted file with a (Conflict XYZ) at the end.
However, in practice, when syncing files between Windows and Mac clients this is not the case. In the case of a conflict the Mac client will always overwrite the edits made in a file by a Windows user who made changes at the same time.
This might be connected to this problem: Shared cryptomator folder doesn't update for Mac users