[Call Blocking]iOS14.5&14.5.1 Call Blocking Unstable!

In the iOS14.5&14.5.1 Upgrade release note mentioned that the problem of "call blocking and identification may not be displayed in setting" has been fixed. However, after updating to iOS 14.5, the original normal [setting - telephone-call blocking and identification] option has disappeared. When re-installing the call blocking app, the option may recover, but it will automatically disappear after a while, becoming very unstable.
How to solve it?
Every time when I check the [setting - telephone-call blocking and identification] option, the option is disappear , and I wait for 30second ,the option appear, what the strange waiting?
[Call Blocking]iOS14.5&14.5.1 Call Blocking Unstable!
 
 
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