Hello,
To isolate the issue, disable anti-virus software and verify the result.
Are there any other applications running at the same time of the bakup? If so then stop it and check the results.
Also as mentioned by you, the service crashes after backing about 40GB, please split this job into two and check if it gives you the same problem.
Are there any specific alerts prompted before crashing of this service ?
Kindly update.
Regards,
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