Whoops! Something went wrong!
Don't worry, this is surely our fault. We've just logged this error and someone should be checking on what happened soon!
That was the message I received after attempting to add my BurnerMail email address to my list of Gravatar's addresses. Until it gets fixed, I shall remain a gray ghost on WordPress.com. I don't really care, though.
The main function, getting those notifications out of my main email Inbox, works quite well. I can read the blog posts when I get free time.
Update 1/29/2021: After visiting WordPress.com, things seemed to be all better: I was able to add my image to my BurnerMail address, which is, of course, my primary address for WordPress.com.