Zendesk iOS SDKs [Error : "The connection to service on pid 87 named com.apple.commcenter.coretelephony.xpc was invalidated from this process."]

Question

Tried to implement ZenDesk iOS SDK as per their documentation:

https://developer.zendesk.com/documentation/zendesk-web-widget-sdks/sdks/ios/getting_started/#show-the-conversation

the chat interface is not displaying as said in the documentation, instead we got an error

[Client] Updating selectors after delegate removal failed with: Error Domain=NSCocoaErrorDomain Code=4099 "
The connection to service on pid 87 named com.apple.commcenter.coretelephony.xpc was invalidated from this process." 
UserInfo={NSDebugDescription=
The connection to service on pid 87 named com.apple.commcenter.coretelephony.xpc was invalidated from this process.}

We use: Xcode version: 12.5.1 Swift version: 5.4.2

is there any solution for this error?