iPhone not recognizing hearing aids with 15.4 update

Hello, and thank you for using Apple Support Communities.

Double check and confirm your hearing aids are compatible with iPhone: Made for iPhone compatible hearing devices - Apple Support

Then start with a restart of the iPhone. Sometimes a restart can help resolve issues: Restart your iPhone - Apple Support

When trying to pair the device, are you using the steps here? Use Made for iPhone hearing devices - Apple Support

"Pair and connect

When you pair a Made for iPhone hearing device to your Apple device, audio from your Apple device goes to your hearing device. If you turn off your hearing device, you need to reconnect it when you want to use it with your Apple device again.

To pair your hearing device, follow these steps:

1. Make sure that Bluetooth is on. Go to Settings, then select Bluetooth.
2. Open the battery doors on your hearing device.
3. On your Apple device, go to Settings > Accessibility > Hearing, and select Hearing Devices.
4. Close the battery doors on your hearing device. Your Apple device will search for your hearing device.
5. Under MFi Hearing Devices, tap the name of your hearing device.
6. Tap Pair when you see the pairing request on the screen. If you have two hearing devices, you'll get two requests. Pairing could take up to a minute.

You can start using your hearing device when you see it under MFi Hearing Devices with a check mark. Control on Lock Screen will be on. Leave it on to control your hearing device from the Lock screen (using the Accessibility Shortcut) and from Control Center on your iPhone or iPod touch, or Control Center on your iPad."

If you still have troubles, see if this article helps: If you can't connect a Bluetooth accessory to your iPhone, iPad, or iPod touch - Apple Support

"If you can't connect to one of these devices

• Get help connecting your iOS device and your car stereo.
• Learn how to set up your AirPods.

To get help pairing a Bluetooth accessory—like a wireless keyboard—to your iOS or iPadOS device, try these steps:

1. Make sure that your Bluetooth accessory and iOS or iPadOS device are close to each other.
2. Turn your Bluetooth accessory off and back on again.
3. Make sure that your Bluetooth accessory is on and fully charged or connected to power. If your accessory uses batteries, see if they need to be replaced.
4. If there's an app that you use with the Bluetooth accessory, go to Settings > Privacy > Bluetooth on your iOS or iPadOS device, and make sure that you've turned on Bluetooth for the app.

If you still can't pair or connect your Bluetooth accessory

1. If you previously connected your Bluetooth accessory to your iOS or iPadOS device, unpair the accessory, put it back in discovery mode, then try to pair and connect it again.
2. If you can pair your accessory with some devices but not your iOS or iPadOS device, unpair the accessory from your other devices. Then try to pair with your iOS or iPadOS device again.
3. Check with the accessory manufacturer to make sure that your accessory supports your iOS or iPadOS device.
4. If you still have any of these issues, contact Apple Support: 

• You can’t turn on Bluetooth or the setting is grayed out.
• You can’t connect any Bluetooth accessories with your device.
• The accessory manufacturer confirmed that your accessory is working correctly."

You may need to contact the manufacturer incase there are any updates.

Best regards.

IOSbugs,

As you're still experiencing issues, and it just started after updating, we'd recommend reaching out to Apple Support directly for a deeper investigation.

This page can help with starting the support request: Get Support

Cheers.

I had the same problem after the update but a restart of the phone solved the connection problem. I also had to go back to accessibility to reset access to hearing devices in triple click.