There are no null names. There is only one attachment per user in this flow.
This is the download from the failure:
{"statusCode":400,"headers":{"Cache-Control":"no-store, no-cache","Pragma":"no-cache","Set-Cookie":"ARRAffinity=ef60c7efc411e7a2234239102c2b4e8d94db8fa5e2ba182ac3091a4caeeeaf0b;Path=/;HttpOnly;Secure;Domain=office365-ncus.azconn-ncus-001.p.azurewebsites.net,ARRAffinitySameSite=ef60c7efc411e7a2234239102c2b4e8d94db8fa5e2ba182ac3091a4caeeeaf0b;Path=/;HttpOnly;SameSite=None;Secure;Domain=office365-ncus.azconn-ncus-001.p.azurewebsites.net","Strict-Transport-Security":"max-age=31536000; includeSubDomains","x-ms-request-id":"cc9d0f8e-8330-49bd-9317-c030c3320cec","X-Content-Type-Options":"nosniff","X-Frame-Options":"DENY","x-ms-environment-id":"default-0e643b65-4bb3-40b7-9887-0c811aaef60f","Timing-Allow-Origin":"*","x-ms-apihub-cached-response":"false","x-ms-apihub-obo":"false","Date":"Tue, 14 Nov 2023 23:02:22 GMT","Content-Length":"306","Content-Type":"application/json","Expires":"-1"},"body":{"status":400,"message":"Parameter 'Attachment Name' cannot be null or empty.\r\nclientRequestId: cc9d0f8e-8330-49bd-9317-c030c3320cec","error":{"message":"Parameter 'Attachment Name' cannot be null or empty."},"source":"office365-ncus.azconn-ncus-001.p.azurewebsites.net"}}
