ADE refuses to authorize on Kobo any more

I believe I know what the cause of my problem was, but I cannot find a solution. Multiple attempts to chat with support on the dedicated ADE page were no help.

I recently changed my Kobo email address, which changed my Rakuten ID. I believe this is the cause of my problem: ever since I changed this, ADE on my Kobo Libra 2 refuses to read library books that I download from Overdrive (but I can read them just fine on ADE on my computer for some reason, and ADE works normally on Overdrive books that transfer over wifi).

When I upload the books to my Kobo and try to read them, I get this error message:

Oops! This document couldn't be opened
This document is protected by Adobe Digital Rights Management (DRM) and is not currently authorized for use with your Adobe ID. Please sign-in with the authorized Adobe ID and try again.

I have done all the steps. I have unauthorized and reauthorized Kobo and computer, I have rebooted Kobo and computer, I have uninstalled and reinstalled ADE on computer, I even did a full factory reset of my Kobo. Still no fix. I have the most recent version of ADE (4.5.11) installed.

I assume the issue is that my Adobe account was tied to my old Rakuten ID somehow and needs to have that "reset"? But I can't find a way to do that.

ADE will open