I will be very appreciate for help.
The problem is with the PST file when using Windows File system agent.
After executing a full backup job, the PST file is not backed up in successive increments, despite the daily modification of the file. The client tried to turn off the application in front of the backup window, restarted the computer and the agent was updated as well.
From the subclinet side, the settings are as follows, although the PST file is not backed up every day during incremental jobs.
Best answer by kszafView original