Look for KB5022913 in optional updates
Windows 11 version 22H2 had an unexpected and unwanted surprise of slow performance when copying large files from a remote machine or server. For users who have updated Windows, SMB copy speeds can plummet in many remote copy sessions and sometimes even in local copies. Although we have not received formal notification of the actual impact, we have seen a 50% increase in copy times for users affected by the issue.
The new patch was tested on Windows 11 preview build 25252 and resolved the issue without any negative impact. As a result, KB5022913 has been released and is now available for testing on Windows Update. If you’re concerned, start testing now as it will be rolling out to everyone on Patch Tuesday next month.
If you want to avoid this entirely, use robocopy and xcopy. These don’t use buffered I/O, so the issue doesn’t affect them at all. Bleeping Computer has some details and history regarding this unfortunate bug. See if you’re interested.
