Since recent updates, iTunes not recognizing iPod Touch

I sync music from iTunes to two iPod Touches (6th Gen, both running iOS 12). My MacBook Pro is running the latest version of High Sierra.

Today, I attempted to sync both of these iPods, and iTunes would not recognize either one (although I got the notices to trust and responded accordingly). I went through all the troubleshooting steps, restarted all the devices, even tried on another MacBook Pro that accesses the same library--same result. I tried the various usb ports and tried different cables. Finally called Apple Support, who went through the exact same steps with the same (non) result that I got. Eventually we did the data capture and uploaded the logs to Apple and I now have an open ticket.

Is anyone else experiencing anything like this? The only thing I can conceivably relate it to is recent updates to High Sierra and/or iOS. I don't recall exactly the last time I synced my iPods, but it was within the past 3 weeks or so. Everything worked fine then, and today everything just pretty much went to ****.