New iMac M4 Sequoia 15.5 does not allow you to sync music from an external drive

After years of just working with a Mac Mojave 10.14.6 I decided to get a new one due to all of the updates on other apps that the old Mac would not sync with. I never went further in updates because I LOVE iTunes. I have a very large music library, taking up 3TB on an external drive.

I was told some years ago that you could merge iTunes with Apple Music, playlists and all. Both my wife and I have iPhones with Apple Music and we have been able to sync playlists from iTunes to our phones for years.

However, my wife's phone is newer and she recently did a software update and now we can no longer sync iTunes with her phone. But that is another story...

I was on the phone with an Apple specialist for HOURS yesterday, allowing him to screen share on both of my Macs. He even consulted a colleague after coming to the conclusion that the new M4 does not allow you to sync with an external HD. It's either drag files from drive into the Mac or use the cloud. I've enclosed some screenshots, not knowing how Apple Music showed up before the M4. Note the red dots with - signs in them in the pathway to external drive in the last shot.

If this is indeed the case, shame on Apple....