Apparently, this was fixed in iOS16.2 based on the info provided in the stackoverflow thread you have provided.
razlat
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Following up on @spencer602's comment: in my case, in a SwiftUI app, a `.blur()' modifier applied on a close-to-root view / root view was making the 'Enable dictation' alert disappear when tapping the microphone button on the keyboard. So I think a general recommendation for cases where the 'Enable dictation' alert disappears would be the following: check app related callbacks (willResignActive, didEnterBackground) for any first responder manipulation, if that's not the case, make sure you are not altering the view hierarchy in any way when app resigns active / goes into background.
Based on Xcode 15 release notes, this is a known issue that does not seem to be on Apple's plate:
"Xcode 15 may not be able to communicate with devices running iOS 17+ and tvOS 17+, and Apple Watch devices paired to an iPhone running iOS 17+ with certain VPNs active. (110337781) (FB12243540)
Workaround: Disable the VPN to interact with the device and reach out to the VPN vendor for resolution."