iPhone Bluetooth will not connect

[BobHas]

I just updated my iPhone 12 Pro Max from 18.3.x to 18.4.1.
All seems well, including connecting to my High Sierra system and my Catalina system.
BUT, now it will not connect to my Monterey 12.7.6 systerm. I can see it and try to connect. It seems to do that momentarily, then disconnects again.

A clue - after the iOS update the connection was a bit odd (don't recall the exact details) and the either in that session or shortly after I got a window that said something about needing to load a software item, which I did. Something to do with compatibility.

I tried doing remove and reconnect, and got a slightly odd back and forth about a six digit code. On the phone there was I think basically just allow the connection - with the code.

Anyone else?

Ideas?

 

[ferrarr]

Did you restart your device(s)?

What procedures exactly do you do to connect through Bluetooth? I don't specifically "connect" in Settings -> Bluetooth, so I just want to understand?

 

[BobHas]

Oh yes, I restarted the Mac via the Apple in the menu bar, and I powered down then started on both the Mac and the phone.

I tried everything I know on the Bluetooth I think (but that has been a bit limited)

Now I am looking at at the Bluetooth System Preference panel. I see the phone on the list and it is marked not connected. I right click and click Connect. Nothing happens. I also note Now discoverable as "iMac" (iMac" is the name of the Mac in question here.)

Now, on the phone in the Bluetooth screen I see the Mac at the bottom I see other devices. The Mac is there (and oddly something called DESKTOP-IV5C286 that I have no idea about). I click the Mac and I get "Pairing Unsuccessful "iMac is not supported" and OK which I click.

I am thinking something is broken in the connect process - maybe some security thing - quite possibly related to the odd install I mentioned.

 

[ferrarr]

and oddly something called DESKTOP-IV5C286 that I have no idea about)

That sounds like a winOS PC nearby. I get them from my kids winOS PC's, but it could be Linux too for all I know.

"Pairing Unsuccessful "iMac is not supported"

That sounds like the Mac itself, not the macOS, isn't supported in iOS 18.4.1.

 

[BobHas]

Yes, there is a Windows machine nearby, but I never saw it show up before - but then I only look very infrequently, and also the OS on thr PC keeps getting updated...

"That sounds like the Mac itself, not the macOS, isn't supported in iOS 18.4.1."
Well, if so, without any notice it would seem odd. It would be change between 18/3 and 18.4.

Hoping some one else has seen this too.

 

[Rod]

I think the first thing I would do is "Forget" this device in the information section for the older Mac on your iPhone and the same on your Mac for the iPhone.
Allow your iPhone to "find" your Mac in Bluetooth Settings and or vice versa on your Mac.

In other words try to setup a new "pairing" between the devices. This may prompt the iPhone to request a download of any software necessary to connect to Monterey as it did before.