High Sierra iTunes 12. not recognizing iPhone running 15.7.6

A week ago, my mac pro 2012 was running Yosemite. At that point I made a backup of my phone, a 6s. currently running iOS 15.7.6

I then upgraded my mac it to High Sierra.

The night before, my phone updated to 15.7.6 from 15.7.5

Now, when I plug my phone in, this comes up:

A software update is required to connect to {name of phone}

With option to install or "later"

If I click Install I get this about 2 seconds later.

Installation Failed.

Can't download the software because of a network problem.

Repeating this on my wife's High Sierra machine, it downloads installs the patch, and her mac can link to my phone.

I can reproduce this problem with what should become my new phone a iPhone 11 Pro max running 16.5.1

From my reading the problem is a program called MobileDeviceUpdater

I have a 48K crash log that makes no sense to me.

I have put a copy here:

Anyone who has the link can view.

I'm going to try a reinstall of High Sierra.

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