I appreciate you trying the steps mentioned to fix the issue. Since it doesn't work on your end, I suggest reaching out with our QuickBooks Desktop Support to check and investigate this further for you.
intuit data protect is not working automatically after i setup the daily auto backup
I've encountered this issue in a similar setting (shared QB install with several RDP users on a single server), and have discovered that this is occurring because of the Intuit Data Protect program being configured as a startup item for 'All Users' (rather than the 1 user that is running IDP backups). The IDP software will only open one instance, so when it's running under another account (other than the one configured to backup using IDP), it fails to work properly.
The IDP software is configured to start automatically via an 'All users' start up item that's located within the folder at C:\ProgramData\Microsoft\Windows\Start Menu\Programs\Startup. However, that causes the startup item to be launched by any user. More specifically, it means that it will open under the account that logs into the server first after a startup/restart.
From what we've found, IDP needs to be launched by only the user that has scheduled IDP backups. This can be done by moving the Intuit Data Protect shortcut from the 'All users' start up items folder, and into the individual start up items folder (for the user that's configured to run IDP within QB) at: C:\Users\<username>\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup.