Hello Walt Nesbit,
Welcome to the Microsoft Community.
I understand that you encountered an issue while trying to redeem your Office product key. This error might indicate a server-side problem causing the user interface to be unstable. Similar issues are usually resolved after some time.
You can also try using a different browser to download the product. Sometimes, browser cache or profile errors can cause webpage issues.
On the other hand, if you have already seen the product download page, it means the key has been redeemed to your account. You can try downloading the files from your Microsoft account page. Visit account.microsoft.com and go to "Subscriptions" to check if your subscription appears there and install it.
Considering your post is in the Mac section, after ensuring your subscription has been added to your account (check the "Subscriptions" section on account.microsoft.com for this product), you can download the Office for Mac application from this link and log in to your account to activate it: Update history for Office for Mac - Office release notes | Microsoft Learn

I hope this information helps you!
Best RegardsEliac | Microsoft Community Support Specialist