Version conflicts

[JLReeher]

Will try to make this as short as possible. I have a 2015 iMac. Have created over the years a 2000 song library organized into playlists. My songs come from a myriad of places, my CDs, my vinyl albums converted to MP3 and songs downloaded from the internet as MP3s. I used to be able to simply plug the iPhone (or iPad) into the computer and sync my library. My iPhone 12 Pro Max used to work untilI upgrade it’s version to 15.4.1. Now it won’t sync with iTunes using Mojave 10.14.1. I’ve spent more than 20 hours on the phone with Apple Support. They finally suggested I upgrade the computer to Monterey. I was hesitant to do that because I had tried Monterey before and had all kinds of problems.
So I gave in and upgraded to Monterey. It was a disaster. Even the Senior Advisors couldn’t figure it out. So I erased the computer completely and restored from Time Machine. But I still can’t sync the iPhone. As a matter of fact, it doesn’t even show in Finder when plugged in with a USB cable. It shows in iTunes but with goofy information.
What I have learned is that the iPhone version was built for communicating with the 64 bit platform. So my question is how can I put a previous version on the phone (and iPad) to work with Mojave.
Thanks for any help.

 

[chrfr]

Will try to make this as short as possible. I have a 2015 iMac. Have created over the years a 2000 song library organized into playlists. My songs come from a myriad of places, my CDs, my vinyl albums converted to MP3 and songs downloaded from the internet as MP3s. I used to be able to simply plug the iPhone (or iPad) into the computer and sync my library. My iPhone 12 Pro Max used to work untilI upgrade it’s version to 15.4.1. Now it won’t sync with iTunes using Mojave 10.14.1. I’ve spent more than 20 hours on the phone with Apple Support. They finally suggested I upgrade the computer to Monterey. I was hesitant to do that because I had tried Monterey before and had all kinds of problems.
So I gave in and upgraded to Monterey. It was a disaster. Even the Senior Advisors couldn’t figure it out. So I erased the computer completely and restored from Time Machine. But I still can’t sync the iPhone. As a matter of fact, it doesn’t even show in Finder when plugged in with a USB cable. It shows in iTunes but with goofy information.
What I have learned is that the iPhone version was built for communicating with the 64 bit platform. So my question is how can I put a previous version on the phone (and iPad) to work with Mojave.
Thanks for any help.

You cannot downgrade the operating system on your phone and iPad, but if you're really running 10.14.1, and not 10.14.6 with the related security updates, you definitely need to update to there and see if things start working again. You could also go to Catalina or Big Sur and either of those will also work with the current versions of iOS/iPadOS.

 

[JLReeher]

Yes sorry. 10.14.6. I’ll look into Catalina. The problem is having to go through iCloud as many of the songs won’t transfer. Apple claims it is because of copyright issues. I have a major problem with that because they aren’t the police and it doesn’t explain why songs I have put on the computer from my albums that I’ve owned for over 40 years won’t show. That’s a subject for another discussion.