I see you are sharing a large video file. In this case, it is recommended to use our client software and group account features. The client software -- DriveHQ FileManager is like FTP or Windows Explorer. Please note if you shared the folder to group members, they (sub-users) should logon their own accounts, and access the shared folders in the virtual folder :
Otherwise, please make sure you have entered their email addresses when sharing folders to them. It seems you have only entered your own email address -- in which case, you are only sharing with yourself.