Hello there, thales.

Thanks for keeping us posted and for sharing the steps you've done so far.

I've checked the investigation status about this issue, and it's still in progress. Our engineering team are continuously working in search of a resolution for this Error 404.

While we work on fixing this issue, I recommend you get in touch with our Care Support Team so they can add your company details to the list of affected users.

Here's how you can reach them:

1. Sign in to your QuickBooks Online company.
2. Click the Help icon in the upper right of the screen.
3. Select Contact US on the pop-up. 
4. Enter what you're needing assistance with in the How can we help? field and choose Continue. 
5. Click Get a callback.
6. Enter your contact information.
7. Select Call me.

If the status of the behavior changes, we will be sure to communicate that to you through this thread.

We appreciate your patience while we continue working on getting this resolved. Stay in touch for updates and if you have any other questions, feel free to leave a reply below.