iPhone 13 Bluetooth audio not working after iOS update

Bluetooth audio issues on an iPhone can stem from several different causes. Some of the most common include:

1. Device not connected properly: The Bluetooth accessory may not be paired or connected to the iPhone. Always check in Settings → Bluetooth to confirm the device shows as “Connected.” If not, try re‑pairing it. Connect a third-party Bluetooth accessory to your iPhone ...
2. Interference from other signals: Bluetooth operates on the 2.4 GHz frequency, which is also used by Wi‑Fi routers, microwaves, and other wireless devices. Too many signals in the same area can cause interruptions or poor audio quality. Moving closer to the iPhone or away from other electronics often helps.
3. Defective or incompatible device: If the Bluetooth accessory itself is faulty, outdated, or not fully compatible with iOS, audio may cut out or fail to play. Testing with another Bluetooth device (like AirPods or a speaker) can help confirm whether the issue lies with the iPhone or the accessory.
4. Distance between devices: Bluetooth has a limited range—usually around 10 meters (33 feet). If the accessory is too far from the iPhone, audio may drop or fail to connect. Keeping the devices within close proximity ensures a stable connection.

Hi, your iPhone 13 should be upgraded to the latest version, currently iOS 26.5. The upgrade will likely resolve any Bluetooth issues.

Update iOS on iPhone - Apple Support

Based on the title of the post: "After iOS update"

Not every issue an individual encounters on their device can be attributed to an iOS update. If the update itself were the root cause, then every device running that same version of iOS would exhibit the identical problem. In such a scenario, the forums would be flooded with countless posts reporting the same malfunction, creating an unmistakable wave of complaints that no one could possibly overlook. The absence of such widespread reports strongly indicates that the issue is not systemic, but rather specific to the device in question.

You may get better and prompt responses if you may kindly provide the iPhone Model that you have and the iOS version if it is known to you and re-post.

With the limited information that you have provided, It is hard to even guess the problems faced by you. 

You may get faster and better responses to your query by --> Writing an effective Apple Support Commun… - Apple ...

Please re-post with detail so that someone else can help.