The fix is arriving through the optional KB5067036 update for Windows 11 25H2, which Microsoft began rolling out last week.
Windows Latest says Microsoft never acknowledged the longstanding problem until releasing an optional update on Oct. 28. A ...
Starting with Windows 11 25H2 Build 26200.7019 (or 26100.7019 on 24H2) and newer, “Update and shut down" will shut down, not reboot.