About this bug, Apple Developer Technical Support  said There is no workaround DTS. it is still under investigation. Please continue to track the problem via the bug report. Is Apple not aware of this issue? No action about this bug from iOS 14 released date.

@thuann4 Not yet. No reply gotten while 1.5 months. My feedback(#FB8884824) status is still Recent Similar Reports:None/Resolution:Open.

@ thuannh4 Sorry, My feedback is from my companies business account. I think it's the same issue, but let's patiently ask to Apple as a each issue. Hello, someone of inside Apple! Please, see this thread and fix this bug.

iOS 14.4 Beta 2 still has this bug. Please, check this issue!!

iOS 14.4(RC) still has this bug. Does anyone have work around about this bug??

On iOS 14.5 beta 5 Phone Settings - 'Call blocking & Identification' menu is delayed to shown while 30 seconds. This problem is from iOS 14.5 beta 2. also, iOS 14.5 beta 5 has this problem. And, CallDirectory Extension app CXCallDirectoryManager.sharedInstance.getEnabledStatusForExtension method consumes between 30 seconds to call completionHandler and throws error first calling. This is critical bug for Call Directory Extension app. my Feedback no is FB9052497.

iOS 14.5 beta 6 still has this critical bug..

iOS14.5 beta 7 also has this bug. Does Phone menu creating process call sleep(30000) before drawing???

iOS 14.5 RC also has this bug. Apple does not fix this problem.

This is fixed by iOS 14.5 beta2. Today, iOS 14.5 was released. But, iOS 14.5 has new bug about CallDirectoryExtension. see https://developer.apple.com/forums/thread/670737

iOS 14.6 beta 2 still has this bug.

@Banck Yeah, I did. I confirmed this problem was fixed on 14.6 RC.