How to make an iPhone Ringtone my Mac - Sonoma OS?

Hi --

I am attempting to create ringtones for my iPhone on my Mac. The details:

Mac mini M1, OS is 14.6.1

Music version is 1.4.6.32

iPhone 14 Pro, iOS 17.6.1

My audio editor is Sound Studio 14.10

My source songs are Apple Lossless -- burned from CDs that I own.

I am using directions that I found in MacWorld. (https://www.macworld.com/article/616018/how-to-custom-ringtone-iphone.html)

I created some 30-second m4a AAC files using Sound Studio and changed them to m4r using Finder.

From there, I am supposed to drag the m4r files to my iPhone, which is connected to my Mac via USB.

In Finder, I select and open the iPhone.

I drag the m4r files from the Mac and get the + sign indicating that the files have been imported.

I am supposed to find the new ringtones in Sounds & Haptics, but they are not there. Ringtones that I created multiple years ago are listed.

Help, please. I'm stuck. Have I missed a step?

Thanks!