There are purchased items not transferred to the Mac. What can I do?

I have been browsing through old threads on this same issue and the replies mention (1) do a backup of the iPhone or (2) perform a SYNC operation. Well neither option solved the situation for me as I am yet unable to understand what is really going on.

We're in 2025, iOS 18.4 just came out and this still happens!

Does anyone have an update on this, please?

One small detail I noticed a few minutes back: behind the Finder window where I was clicking "Update" repeatedly, a dialog box had come up (hidden behind the Finder) saying a software update was needed before I could update my iPhone 14 Pro Max. Even after allowing the download, the "not transferred to Mac" message still shows. As I have done through the ages, I just clicked on "Continue" and iOS 18.4 is now installed.

Hope this reignites the thread and that we can finally get a final, true, solution.

-Fernando