17.5.1 System unable to use multicast

After downloading the Testflight app, the iPhone 15 Pro Max 17.5.1 phone cannot use multicast function, but it can be used normally after restarting the phone. There will be problems with reinstalling and restarting the app. But there are no issues with other phones or system versions. May I ask if this is a defect in the 17.5.1 system?

17.5.1 System unable to use multicast
 
 
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