Why can't I use my Dorico Pro 5 coupon?

I purchased Dorico Elements 4 from the official website in the first half of this year, and recently discovered that I have a download access code for Dorico 5 in my Steinberg account, but the activation prompts the following:
Something went wrong. Please contact your local support team and have the error-code “dre-426” ready.
I don’t know what went wrong.

It looks to me as if you have an appropriate Dorico Elements 4 license associated with your Steinberg ID. Could you please send me a private message here on the forum with the Download Access Code you’ve received for your grace period update, so I can follow up with a colleague and see what might be going on?