As far as I know, this only happens with certain anti-virus, anti-malware or similar interfering with the I/O, but that should have been solved by a restart. Yours is the only example I've seen of this particular problem, so I doubt you'll see it again. If you do, go though the basic trouble-shooting steps of switching off temporarily every suspect - AV, Windows Defender, firewall, indexer etc. etc. - until you find the culprit. Or use something like Process Explorer to inspect any open handles on the file. This is assuming that your Status Code 0 prob was not related here. In any case, you can be 99.9% certain that speed throttling has nothing to do with it.