I'm also getting the same issue, and re-creating the FTP connection doesn't work.
Connecting using a public key
SBSimpleSftp.EElSimpleSFTPClientError: Connection error 111
at SBSimpleSftp.TElSimpleSFTPClient.Open()
at MIFBJIBNICCMJFNICMEPLMKAMAEFBBOJGLEK.OCHLGMNAHFPMFFMCCEGDNFOLGPFBABHFGOFM(Object , MIFBJIBNICCMJFNICMEPLMKAMAEFBBOJGLEK )
at ctlRemoteBrowser.ConnectThread(Object connectionObject) in C:\git\code\VisualCron\Connections\ConnectionExplorer\ctlRemoteBrowser.vb:line 1605