How can I stop iPhone switching to Bluetooth mid-call?

[Mildredop]

This is one of those iPhone quirks that makes me think no-one at Apple actually uses iPhones.

Very often I’ll make or receive a call completely on the iPhone and then, after a minute or so, the iPhone will suddenly decide to connect to some Bluetooth device that I didn’t even realise was on (could be a speaker in a different room or headphones in my bag).

It also happens when using a Bluetooth speaker - it’ll suddenly decide to connect to a different Bluetooth device (this most often happens when I’m working in my garage listening to music. If I switch on the ignition of my car, it flips to the car).

How can I stop this irritating “quirk”?

 

[usagora]

Please let me know if you find out. This happened to me the other day with my AirPod Pros. I had taken them out and set them on the counter. Received a call from somebody and answered it on my iPhone, but my AirPods immediately took over the call even though they weren't in my ears.

 

[Mildredop]

The lack of replies is making me think usagora and myself are the only people who have this issue. Surely that isn't the case?

 

[now i see it]

Maybe your phone has developed a hardware defect

 

[addamas]

I could only confirm that I never had this issue

 

[Mark Stone]

I set up the iPhone 8 Plus I used to own to pair with my car, and occasionally I would start talking on the phone and it would switch over to the car when I didn’t want it to. My solution was to un-pair the 8+ and the car (permanently), and to not pair my new 13 with the car at all. When your iPhone is paired with many similar devices, probably the only way to control its roaming is to either unpair or turn the devices off. I think it would help if iPhone had some appropriate settings to easily control these issues. I agree with @Mildredop that Apple employees are probably using Undroids.