iPhone 7 Plus phone call issue after update iOS 12.0.1

Trying putting device in recovery mode while plugged into iTunes. Once you see a pop up that says device needs to be updated or restored click on ‘update’ Incase there’s were any bugs in the software this will take off the software and replace it with new software without losing everything on your phone.

https://support.apple.com/en-us/HT201263

Let us know if this works.

You can also contact Apple support and they can run a diagnostic on your device to see if there’s anything wrong with your device (hardware, software related) and if so they can get you scheduled for an appointment at an Apple authorized retailer or Apple retail store.

I would first try the above steps! Goodluck, and let us know!

If by "many" you mean two or three people ... out of hundreds of thousands of people who have no issues...

Keep in mind that iOS 12 performs an action that other versions didn't, that of checking the devices hardware for functionality before working. So now instead of the software just blindly working, it checks the device to make sure all hardware parts are fully functional. That doesn't mean that iOS 12 might have an issue, it just means that the new version is now revealing a hardware issue that was previously hidden before.

The bottom line is that there is only one way to know - for sure - what is going on with your device, and that's to take it to Apple for diagnostics. If it's software related they will convey that information to the mothership and fix it, and if it's a hardware issue they will tell you that too, but at least you'll know one way or the other what is actually causing your issue.

The next step is to restore iOS: Restore your iOS device to factory settings - Apple Support

Most likely this is caused from either some corrosion under the audio chip, or someone used non-apple parts in the phone. It's not the update because my iPhone 7 Plus works fine (with newest update) and several other people that I know who also have the update installed on the same phone have no issues either.

Well, it appears to be a problem with your phone, not with the update. Have you done any troubleshooting thus far?

The most basic step is a reboot: Restart your iPhone, iPad, or iPod touch - Apple Support

If you can't manually record a memo, then most likely it is some sort of corrosion inside the phone under the audio chip...

I just updated to iOS 12.1 this morning (11/13/2018). My phone worked just fine last night before I went to bed. When I woke up this morning, I noticed I had an update available, so I installed the update. An hour after the update, I plugged in my headphones and much to my surprise they weren't working (music was still coming from the phone). Although I was puzzled, I shrugged it off. Then about two hours later, I tried to make a phone call and notice that the call is on speakerphone automatically, with the speaker button greyed out. When the person I was calling tried to answer the phone, I could no longer hear anything and on their end the call dropped. It's not just coincidence that this happened out of nowhere!! My phone was in perfect operating condition prior to this update!!

I contacted Apple Support and they acted puzzled (which, after reading this now I see that as a bunch of BS, because they are perfectly aware of the issue). They instructed me to back my phone up and do a factory restore. So, I'm going to give it a try, although I'm not at all optimistic that it will work!

Right, but this is certainly a software issue. As soon as MANY people updated to iOS 12 this occurred. There's no way this many people suddenly have hardware issues.

I have the same issues on BOTH my iPhone 7 plus devices!

They're not even on the same carrier! I've tried everything including restoring as a new phone, NOTHING.

This isn't annoying, it straight up breaks the phone.

These last few updates have been embarrassing with the amount of feature breaking bugs they've been introducing.

Time to break out the android phone again while apple takes their time fixing it...

I am having the same problem. I have tried all the usual fixes and am now going to downgrade to IOS 11 to see if the issue still happens.

The phone was recently fixed by an authorised centre and then the day it was upgraded to iOS 12 it has stopped working. Very odd!!!!! And has wasted a lot of my time