Still an issue but now I do have contact with dev support and provided them more details. Hopefully this gets resolved soon.

Do you have WKExtensionDelegateClassName with value $(PRODUCT_MODULE_NAME).ExtensionDelegate in your extension's Info.plist file? And the delegate adaptor in the App: @main struct Mypp: App {    @WKExtensionDelegateAdaptor(ExtensionDelegate.self) var extensionDelegate Latter produces a SwiftLint warning though: Weak Delegate Violation: Delegates should be weak to avoid reference cycles. (weak_delegate) Adding weak produces an error. Don't know what to do with this, so currently I have to live with the warning.

Well it started working later after I posted my reply. Don't know what was the issue.

Yes, same issues. Rebooted watch, Mac, Xcode but to no avail. I see my developer account details in the Xcode Preferences. I'll contact developer support. Got the following from macOS logs when looking at process Xcode log entries: (Redirect Count) 0 (Transaction Metrics) (Request) {"object":"<NSURLRequest 0x7fd39fce6f10>","url":"https:\/\/devimages-cdn.apple.com\/downloads\/xcode\/dsc\/Watch4_2_18R395.dmg"} (Response) <NSHTTPURLResponse: 0x7fd3892bcf50> { URL: https://devimages-cdn.apple.com/downloads/xcode/dsc/Watch4_2_18R395.dmg } { Status Code: 403, Headers { ... self=<ACSURLSession: 0x7fd389ada4d0> { canUseCachingServer: 1, phase: valid, session: <__NSURLSessionLocal: 0x7fd38951eb60>, delegate: 0x7fd3998df040, tasks: (0x7fd38951ea20) } oletus 16:19:56.611135+0300 Xcode DVTDownloadable: Download Failed. Downloadable: https://devimages-cdn.apple.com/downloads/xcode/dsc/Watch4_2_18R395.dmg. Error Domain=DataWritingACSURLSessionDelegate Code=1 "Failed with HTTP status 403: forbidden" UserInfo={NSLocalizedDescription=Failed with HTTP status 403: forbidden, NSHTTPURLResponse=<NSHTTPURLResponse: 0x7fd38943ce70> { URL: https://devimages-cdn.apple.com/downloads/xcode/dsc/Watch4_2_18R395.dmg } { Status Code: 403, Headers { &#9; ... &#9;&#9;&#9;&#9;"no-store, no-cache, must-revalidate" &#9;&#9;); &#9;&#9;"Content-Length<…> oletus 16:19:59.713998+0300 Xcode iPhoneSupport: Unable to cache symbols for <DVTProxiediOSDevice: 0x7fd389b0a930> device (Error Domain=DVTDownloadableErrors Code=-1 "Could not download and install Symbols for watchOS 7.0.1 (18R395). Failed to download package from ADC." UserInfo={NSUnderlyingError=0x7fd3998e22f0 {Error Domain=DataWritingACSURLSessionDelegate Code=1 "xxx.xxx@gmail.com does not have access to Symbols for watchOS 7.0.1 (18R395)." UserInfo={NSRecoveryAttempter=<_DVTErrorRecoveryHandler: 0x7fd399a08c50>, NSLocalizedRecoverySuggestion=Contact Apple Developer Program Support to resolve account access issues., NSLocalizedDescription=xxx.xxxx@gmail.com does not have access to Symbols for watchOS 7.0.1 (18R395)., DVTRecoveryBlockKey=<NSMallocBlock: 0x7fd3998f0070>, NSLocalizedRecoveryOptions=( &#9;&#9;OK, &#9;&#9;"Contact\U2026" ), NSHTTPURLResponse=<NSHTTPURLResponse: 0x7fd389a6d150> { URL: https://download.developer.apple.com/Developer_Tools/watchOS_18R395/Watch4_2_18R395.dmg } { Status Code: 403<…>

Verifying that this works now.