Unable to download via Kindle app or OpenAudible

Is anybody else unable to download narration via the Kindle for Android app, or via OpenAudible? I was previously able to download from either without issue but now I'm unable to do it for even books I've previously read/downloaded.

In the Kindle app, it just gives a generic "download error". In OpenAudible, it says "No Library Record Found for user." This happens with all books (I have 10 in my library).

I contacted support and they were unable to help. I uninstalled and reinstalled the Kindle app and it didn't help, but since the issue also affects OpenAudible, I don't think the app is really at fault.

The Audible app is able to download without issue. I've got a paid account.

Is anyone else experiencing this issue, or experienced something like this in the past?

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Edit: I also just found that the Windows 10 Audible app gives "Cannot find the title in your library" if I try to download, but it's able to stream without issue.