downloading with flutter downloader... sometimes failes

D/DownloadWorker( 8697): exists file for sample799.pdfautomatic resuming...
D/DownloadWorker( 8697): Open connection to https://x.x.com/api/files/sample799.pdf
D/DownloadWorker( 8697): Headers = {}
D/DownloadWorker( 8697): Resume download: Range: bytes=3028-
D/TrafficStats( 8697): tagSocket(135) with statsTag=0xffffffff, statsUid=-1
2
I/flutter ( 8697): false
I/trustAllHosts( 8697): checkServerTrusted
D/DownloadWorker( 8697): Update too frequently!!!!, but it is the final update, we should sleep a second to ensure the update call can be processed
3
I/flutter ( 8697): false
D/DownloadWorker( 8697): Update notification: {notificationId: 158, title: sample799.pdf, status: FAILED, progress: -1}

Start with the DownloadWorker log path shown in the report and reproduce the intermittent resume failure using the sample799.pdf request. Compare the resume response and final FAILED notification, then document a reliable fix or the missing diagnostic details needed to confirm the cause.

Written by the indexing model from the issue text.