Amazon Alexa Account Linking Throws Session Timeout on redirect

I'm using Amazon Security Profiles (LWA) for a new Alexa skill and following this tutorial: https://developer.amazon.com/blogs/post/Tx3CX1ETRZZ2NPC/alexa-account-linking-5-steps-to-seamlessly-link-your-alexa-skill-with-login-with-amazon

Everything seems to work well. It redirects me to the Amazon login and shows me the scope to grant access. I click allow and rather than seeing the "Your xyz Skill was successfully linked" message I see an error "Your session has timed out" with information to return to my app and log in again to continue using Login with Amazon. I expected it to go back to the Alexa app and say I was good. I have two factor enabled for my Amazon account so I thought maybe that contributed to the timeout but I asked it to not prompt me again for this device and tried again and see the same timeout error message.

We have identified an issue preventing Account Linking preventing to succeed when using Login With Amazon and the Android Alexa App.

Account linking succeed from a desktop browser (Chrome, Firefox, Safari) or the iOS App.

Workaround is to whitelist “na.account.amazon.com” domain in Alexa developer portal.

We will update the system to add this for you by default. I will let you know when available.

[UPDATE Jan 20]
Fix is now live and this problem seems to be solved