Failure to resume log download, and handle resumed operation.

#### Issue details
Log download (over serial port) may fail for no apparent reason with "timeout"
There are two faults:
-failure to retry/resume
-failure to continue download after error, without producing one error for each previously downloaded log.

#### Version
1.3.68.1

#### Platform
[x ] All

#### Hardware type
Cube2.0

#### Logs
see screenshot

Start by reproducing the log download failure over the serial port on the reported Cube2.0 hardware or an equivalent setup, using the screenshot and issue details as the reference. Trace the download flow to determine how a timeout is handled. Done means a failed download can retry or resume, and previously downloaded logs do not each produce another error.

Written by the indexing model from the issue text.