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The hash is recalculated on each client that receives the content, for the particular site, something did alter the content. There's no way to know what did though.
This usually is an issue with antivirus or whitelisting software on the endpoint, you may want to start there.
You may also check below article to see if it helps:
https://www.prajwaldesai.com/sccm-task-sequence-error-code-0x80091007/
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