iTunes on Windows not fully syncing 400GB library to iPhone, but syncs just fine with modded iPod Classic

[Farrgazer]

iTunes version 12.12.9.4, running on Windows 10.

I have a 1TB iPhone 14 Pro Max, and an iPod Classic (7th gen) that has been retrofitted with a 512GB micro SD card.

I've been trying to sync my entire library to both devices. As far as I can tell, everything got copied over to the iPod. But not everything is getting copied to the iPhone. The music storage in my iPhone reads 261GB, and iTunes says something similar.

Anything to try here?

 

[bogdanw]

Have you checked for updates in Apple Software Update?
Apple Support - How to use Apple Software Update for Windows
https://support.apple.com/en-us/HT208038
There may be additional software required to connect to the iPhone 14 Pro Max.

 

[applefan19]

Similar issue here with Mac/iPhone.