I have the same persistent issue on Xcode 26.6 (17F113). Xcode Settings → Components repeatedly fails downloading iOS 26.5.1 + iOS 26.5 Simulator with DVTDownloadableErrorDomain Code 41. xcodebuild -downloadPlatform iOS reaches “Preparing to download” but does not install or export a runtime. Earlier diagnostics reported com.apple.MobileAssetError Code 53: the download was not scheduled or could not complete in time. I have no VPN, no proxy, no Apple entries in /etc/hosts, and over 300 GB free disk space. Xcode’s first-launch component check reports no updates.