iPhone Close Calls problem when bluetooth is Connected.

Hey there VladDudu,

We understand you've noticed that when you answer phone calls while Bluetooth is connected, you can't hear anything. We'd be happy to provide information about this.

It's likely that the audio for the call is being routed to the Bluetooth device. Use these steps to switch the output: While on a call on iPhone - Apple Support

Adjust the audio during a call

To change the volume, press the volume buttons on the side of iPhone. Or swipe down on the call banner, then do any of the following:

* Mute: Tap the mute button.

* Put the call on hold: Touch and hold the mute button.

* Talk handsfree: Tap the audio button, then choose an audio destination.

Kind regards.

Hi VladDudu,

If you haven't already, we suggest checking to make sure you're running the latest iOS version on your iPhone: Update your iPhone or iPad - Apple Support

Updates often resolve unexpected issues with software. Additionally, you may want to try the steps outlined in this article: If you can't make or receive calls on your iPhone - Apple Support

Should the issue persist after trying the steps above, contact Apple Support so that they can look into this with you further. They can be reached here: Get Support

Take care.