Same issue here, just beta 5 that has given issues.

Yeh I'm pretty sure as the others have stated that it's trying to download as the universal XCode when we have silicon only xcode. Without specifying the architecture using the command line it defaults to universal which is what XCode must be doing. ./xcodebuild -downloadPlatform iOS Finding content... Automatically resolved architecture variant for platform iOS as 'universal'. Downloading iOS 26.0 Universal Simulator (23A5308g) (universal): Preparing to download...2025-08-11 10:09:37.520 xcodebuild[32105:573520] DVTDownloadable: Download Failed. Downloadable: { architectures = ( arm64, "x86_64" ); authentication = none; category = simulator; contentType = cryptexDiskImage; dictionaryVersion = 2; downloadMethod = mobileAsset; fileSize = 9663956067; identifier = "com.apple.dmg.iPhoneSimulatorSDK26_0_b5"; isInternalContent = 0; isUserInitiated = 1; name = "iOS 26.0 Universal Simulator (23A5308g)"; patchableFrom = ( ); platform = "com.apple.platform.iphoneos"; simulatorVersion = { buildUpdate = 23A5308g; version = "26.0"; }; version = "26.0.0.5"; }. Download failed. Downloading iOS 26.0 Universal Simulator (23A5308g) (universal): Error: Error Domain=DVTDownloadableErrorDomain Code=41 "Download failed." UserInfo={NSLocalizedDescription=Download failed.}