Can't upgrade Internet Identity and can't login to NNS - a complete nightmare

Just tried logging in to NNS a few days ago for the first time in several months, upon which I discovered an “upgrade” to Internet Identity. I have tried upgrading using two security keys (the one I have used for years to log into Internet Identity version one, and a brand new one). Both fail with the following messages (old key this image, and it appears I will have to put the second image in a different post due to a “An error occurred: Sorry, new users can only put one embedded media item in a post” message).

I have “recovered” my Internet Identity using my seed phrase at least a dozen times. Side rant: my backup only has the first four letters of each word (enough to uniquely identify the word). Why don’t you use a word-picker to display possible words as each letter gets typed, instead of requiring the user to guess the actual word when the first four letters don’t suggest an obvious word? Anyway, recovering my Internet Identity does NOT get me logged in to NNS - I would have thought (and certainly hoped) that it would (when the NNS page sends me to id.ai).

I filed an issue with support a couple of days ago, but have heard nothing since. I have no idea what to do next to access NNS. So far I have wasted about twenty hours on trying to log in, and I have to rank this as one of the worst tech nightmares of my life.

Error message when attempting to upgrade using a new security key:

First of all, welcome to the “community.”

No need to worry friend. I’m sure the support team will be with you shortly.

They are very nice and helpful people.