Podcasts not syncing properly

I'm using MacOS 11.6.2 (20G314) and an iPod Nano. I cannot get podcasts to sync properly.

I have Podcast.app which shows 9 episodes in "Latest Episodes" from 4 podcasts. I have deleted all episodes except for these episodes from the "Downloaded" list.

When I plug my iPod in and select it in Finder, it shows 5 podcasts, 1 of which is a duplicate. When I select any of the podcasts, it shows duplicate episodes, some episodes of which are from different podcasts.

iTunes worked fine syncing until I upgraded to Big Sur, which split everything up.

If I had to guess, Finder is doing a bad SQL join on the SQLite file Podcast.app is writing to. This cross application syncing is obviously completely broken.

The last 4 episodes in this list aren't even for this podcast:

You can see here, the proper place for these episodes, but even still, has duplicates:

After numerous emails and calls with Apple support, they basically gave up and said "we no longer support iPods". This is, of course, after they split up iTunes into Music/Podcast/Finder, and finder was clearly written to handle iPods.

I've rebooted, force-quit Podcast.app (seems to be the only way to kill it; if you just quit, it relaunches instantly without going 'home', indicating it never closed), force-quit finder, re-downloaded episodes, repeatedly unplugged the ipod, twiddled with Podcast.app and Finder sync settings. Nothing works.

When I actually sync everything, they are indeed totally messed up on the ipod just like they show in finder (but not the podcast.app)

What can I do to get this working?