My iPod won’t eject and it just keeps on saying do not disconnect

So I found my mom’s old iPod nano 2nd gen and I’ve been trying to sync my songs from Apple Music and iTunes to the iPod from my iMac OS X El Capitan (early 2008) and nothing is syncing. The iMac is currently using my hotspot from my iPhone 11. I try to sync the songs and it starts syncing for a second then it says stopped. But the iPod already had a bunch of old songs saved to it when I plugged it in. They all popped up when I clicked on the iPod but I tried to eject it and all the iPod does is says do not disconnect then it pops up the apple logo then it just says do not disconnect again. I waited then just disconnected it but then it just restarts the iPod to where it is wiped clean of everything. It has done this over and over again. What do I do 😭🙏