Audio Quality from the Phone is unintelligible

My 2018 limited has the worst audio quality coming from the speakers---I've ever had with any vehicle--- when using the the phone. I have an iphone xr and tested with my wifes iphone as well. When a call comes in or I make a call, I have to switch to choosing the speaker directly from phone to have any kind of conversation and bypass the 4 runners audio system.

The dealer said there's nothing that can be done as the 4 runner speaker is MONO? That does not explain the high pitched, squeaky and scratchy sound. I don't believe his answer. The dealer where I bought the truck said he has the same problem and nothing can be done.

I don't understand this as the audio quality from xm radio, or when listening to AM/FM is fine. I have deleted and re-installed blue tooth connections but the quality remains high pitched and squeaky, scratchy. One of our members must have run into this problem?

 

I bought a different aux adapter for my Samsung to make the audio quality much better. Yes, its not bluetooth. But, the iPhones blue tooth is 5.3 I believe. The head unit in our limited has bluetooth from a long time ago. Unless you can update bluetooth in the head unit, thats all you will get.
Or use a cable to aux.
To be honest, you shouldnt have to do anything, it should just work.