Based on this comment the bot shouldn’t be asking you to sign the CLA for the GitHub noreply email if you’ve signed previously (which I’m sure you have, you’ve been here a while). The CLA site might be erroring because it’s encountering the noreply address.
I am by no means a TypeScript expert, but looking at the code here it seems to be trying to match the username from the noreply email (aa-turner, all lowercase), to your username (AA-Turner). The case differs so presumably it’s not treating it as a match.