What to do when iPod nano is unreadable after macOS Sequoia 15.6 update?

With the 15.6 update I had trouble with my lovable iPod Nano. After messages that the device was unreadable, I at least erased and restored the device. But now when connected to my MacBook Air all I show on my Mac screen is a blank. I can copy songs direct onto the iPod, but can't access them on it. The sync function does not appear anywhere.

Is this a problem with my iPod or the update? How do I solve it?

(Also had to list as a problem with the iPod Touch, but this is a Nano).

[Re-Titled by Moderator]

Original Title: Sequoia 15.6 update and iPod Nano v. 7