SFTP based put fails on first retry but backup succeeds?

I’ve been getting this “Value does not fall within the expected range” error on and off lately (since updating to 2.0.3.3 beta). The error seems to happen during a put retry loop (see Retry @ 10:42) which then succeeds and the backup seems to have a ParsedResult: Success (see Result @ 10:42) however after the a Fatal error is left (see Message @ 10:44) and the job is NOT considered successful (at least according to the job menu Last successful run:Last Saturday at 11:00 AM (took 00:33:28)).

I have two instances of the Retry error that did NOT result in a final Fatal error (3 days ago and a manual run just now) - but I have no idea why they worked while two other runs did not.

Any thoughts?

Apr 16, 2018 10:44 AM: Message
Fatal error
System.ArgumentException: Value does not fall within the expected range.
  at Renci.SshNet.Session.WaitOnHandle (System.Threading.WaitHandle waitHandle, System.TimeSpan timeout) [0x00041] in <502177f7126d48e4be01a83c8cdb4c79>:0 
  at Renci.SshNet.Session.Renci.SshNet.ISession.WaitOnHandle (System.Threading.WaitHandle waitHandle) [0x0000d] in <502177f7126d48e4be01a83c8cdb4c79>:0 
  at Renci.SshNet.Channels.Channel.WaitOnHandle (System.Threading.WaitHandle waitHandle) [0x00000] in <502177f7126d48e4be01a83c8cdb4c79>:0 
  at Renci.SshNet.Channels.Channel.Close () [0x00080] in <502177f7126d48e4be01a83c8cdb4c79>:0 
  at Renci.SshNet.Channels.ChannelSession.Close () [0x00000] in <502177f7126d48e4be01a83c8cdb4c79>:0 
  at Renci.SshNet.Channels.Channel.Dispose (System.Boolean disposing) [0x0000f] in <502177f7126d48e4be01a83c8cdb4c79>:0 
  at Renci.SshNet.Channels.ClientChannel.Dispose (System.Boolean disposing) [0x0000c] in <502177f7126d48e4be01a83c8cdb4c79>:0 
  at Renci.SshNet.Channels.ChannelSession.Dispose (System.Boolean disposing) [0x00000] in <502177f7126d48e4be01a83c8cdb4c79>:0 
  at Renci.SshNet.Channels.Channel.Dispose () [0x00000] in <502177f7126d48e4be01a83c8cdb4c79>:0 
  at Renci.SshNet.SubsystemSession.Disconnect () [0x00053] in <502177f7126d48e4be01a83c8cdb4c79>:0 
  at Renci.SshNet.SubsystemSession.Dispose (System.Boolean disposing) [0x0000c] in <502177f7126d48e4be01a83c8cdb4c79>:0 
  at Renci.SshNet.Sftp.SftpSession.Dispose (System.Boolean disposing) [0x00000] in <502177f7126d48e4be01a83c8cdb4c79>:0 
  at Renci.SshNet.SubsystemSession.Dispose () [0x00000] in <502177f7126d48e4be01a83c8cdb4c79>:0 
  at Renci.SshNet.SftpClient.OnDisconnecting () [0x00017] in <502177f7126d48e4be01a83c8cdb4c79>:0 
  at Renci.SshNet.BaseClient.Disconnect () [0x00006] in <502177f7126d48e4be01a83c8cdb4c79>:0 
  at Renci.SshNet.BaseClient.Dispose (System.Boolean disposing) [0x0000c] in <502177f7126d48e4be01a83c8cdb4c79>:0 
  at Renci.SshNet.SftpClient.Dispose (System.Boolean disposing) [0x00000] in <502177f7126d48e4be01a83c8cdb4c79>:0 
  at Renci.SshNet.BaseClient.Dispose () [0x00000] in <502177f7126d48e4be01a83c8cdb4c79>:0 
  at Duplicati.Library.Backend.SSHv2.Dispose () [0x00008] in <29d74a8631ec474595c3d5eee75c41bf>:0 
  at Duplicati.Library.Main.BackendManager.Dispose () [0x00077] in <ae134c5a9abb455eb7f06c134d211773>:0 
  at Duplicati.Library.Main.Operation.BackupHandler.Run (System.String[] sources, Duplicati.Library.Utility.IFilter filter) [0x008c4] in <ae134c5a9abb455eb7f06c134d211773>:0 

Apr 16, 2018 10:43 AM: Result
DeletedFiles: 0
DeletedFolders: 0
ModifiedFiles: 0
ExaminedFiles: 46378
OpenedFiles: 0
AddedFiles: 0
SizeOfModifiedFiles: 0
SizeOfAddedFiles: 0
SizeOfExaminedFiles: 54758243149
SizeOfOpenedFiles: 0
NotProcessedFiles: 0
AddedFolders: 0
TooLargeFiles: 0
FilesWithError: 0
ModifiedFolders: 0
ModifiedSymlinks: 0
AddedSymlinks: 0
DeletedSymlinks: 0
PartialBackup: False
Dryrun: False
MainOperation: Backup
CompactResults:
    DeletedFileCount: 0
    DownloadedFileCount: 0
    UploadedFileCount: 0
    DeletedFileSize: 0
    DownloadedFileSize: 0
    UploadedFileSize: 0
    Dryrun: False
    MainOperation: Compact
    ParsedResult: Success
    EndTime: 4/16/2018 10:42:31 AM (1523893351)
    BeginTime: 4/16/2018 10:36:40 AM (1523893000)
    Duration: 00:05:50.7963430
    BackendStatistics:
        RemoteCalls: 8
        BytesUploaded: 1786
        BytesDownloaded: 56768583
        FilesUploaded: 2
        FilesDownloaded: 3
        FilesDeleted: 0
        FoldersCreated: 0
        RetryAttempts: 1
        UnknownFileSize: 0
        UnknownFileCount: 0
        KnownFileCount: 1863
        KnownFileSize: 44047373403
        LastBackupDate: 4/14/2018 10:27:17 AM (1523719637)
        BackupListCount: 155
        TotalQuotaSpace: 0
        FreeQuotaSpace: 0
        AssignedQuotaSpace: -1
        ReportedQuotaError: False
        ReportedQuotaWarning: False
        ParsedResult: Success
DeleteResults: null
RepairResults: null
TestResults:
    MainOperation: Test
    Verifications: [
        Key: duplicati-20180404T153119Z.dlist.zip.aes
        Value: [],
        Key: duplicati-ic8d2a11e696f4f5dafa6c5ca634c0e68.dindex.zip.aes
        Value: [],
        Key: duplicati-b24068512e59e462c9bf5478999e7c8a4.dblock.zip.aes
        Value: []
    ]
    ParsedResult: Success
    EndTime: 4/16/2018 10:43:45 AM (1523893425)
    BeginTime: 4/16/2018 10:42:33 AM (1523893353)
    Duration: 00:01:12.0398870
ParsedResult: Success <~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
EndTime: 4/16/2018 10:43:45 AM (1523893425)
BeginTime: 4/16/2018 10:07:22 AM (1523891242)
Duration: 00:36:23.2546050
Messages: [
    Renaming "duplicati-bb2c4f170b67f4efc9cb43b0c129f3b3e.dblock.zip.aes" to "duplicati-bc043ffa4388d490f9aaf39f267e321c4.dblock.zip.aes",
    Compacting not required,
    removing file listed as Deleting: duplicati-bb2c4f170b67f4efc9cb43b0c129f3b3e.dblock.zip.aes
]
Warnings: []
Errors: []

Apr 16, 2018 10:42 AM: Message
removing file listed as Deleting: duplicati-bb2c4f170b67f4efc9cb43b0c129f3b3e.dblock.zip.aes

Apr 16, 2018 10:42 AM: Message
Compacting not required

Apr 16, 2018 10:42 AM: Message
Renaming "duplicati-bb2c4f170b67f4efc9cb43b0c129f3b3e.dblock.zip.aes" to "duplicati-bc043ffa4388d490f9aaf39f267e321c4.dblock.zip.aes"

Apr 16, 2018 10:42 AM: Retry
Operation Put with file duplicati-bb2c4f170b67f4efc9cb43b0c129f3b3e.dblock.zip.aes attempt 1 of 5 failed with message: Value does not fall within the expected range.
System.ArgumentException: Value does not fall within the expected range.
  at Renci.SshNet.SubsystemSession.WaitOnHandle (System.Threading.WaitHandle waitHandle, System.Int32 millisecondsTimeout) [0x0004c] in <502177f7126d48e4be01a83c8cdb4c79>:0 
  at Renci.SshNet.Sftp.SftpSession.RequestRealPath (System.String path, System.Boolean nullOnError) [0x00072] in <502177f7126d48e4be01a83c8cdb4c79>:0 
  at Renci.SshNet.Sftp.SftpSession.GetCanonicalPath (System.String path) [0x0000e] in <502177f7126d48e4be01a83c8cdb4c79>:0 
  at Renci.SshNet.SftpClient.InternalUploadFile (System.IO.Stream input, System.String path, Renci.SshNet.Sftp.Flags flags, Renci.SshNet.Sftp.SftpUploadAsyncResult asyncResult, System.Action`1[T] uploadCallback) [0x00042] in <502177f7126d48e4be01a83c8cdb4c79>:0 
  at Renci.SshNet.SftpClient.UploadFile (System.IO.Stream input, System.String path, System.Boolean canOverride, System.Action`1[T] uploadCallback) [0x00017] in <502177f7126d48e4be01a83c8cdb4c79>:0 
  at Renci.SshNet.SftpClient.UploadFile (System.IO.Stream input, System.String path, System.Action`1[T] uploadCallback) [0x00000] in <502177f7126d48e4be01a83c8cdb4c79>:0 
  at Duplicati.Library.Backend.SSHv2.Put (System.String remotename, System.IO.Stream stream) [0x00012] in <29d74a8631ec474595c3d5eee75c41bf>:0 
  at Duplicati.Library.Main.BackendManager.DoPut (Duplicati.Library.Main.BackendManager+FileEntryItem item) [0x001fa] in <ae134c5a9abb455eb7f06c134d211773>:0 
  at Duplicati.Library.Main.BackendManager.ThreadRun () [0x000da] in <ae134c5a9abb455eb7f06c134d211773>:0